For almost a decade, Oliver L. North has been dogged by questions about what he did to make sure U.S. government flights to help the Nicaraguan contras were free of drug traffickers.

In personal diaries North kept in 1985, he wrote down a trusted aide's tip that drugs were being brought into the United States on a contra supply plane. He recorded the type of aircraft and a stop on its route -- New Orleans. In testimony he gave to Congress in 1987, North said he gave that information to the Drug Enforcement Administration.

But the DEA, when asked to verify North's testimony, issued a statement Friday saying, "There's no evidence he talked to anyone. We can't find the person he talked to, if he did talk to them. There's no record of the person he talked to."

Along with the new DEA comment, government records, depositions, hearing testimony and interviews with former officials, the diary entries again raise questions about what North did to maintain the integrity of the contra supply efforts that he oversaw as a National Security Council aide.

North declined to grant an interview for this story, and he did not respond to written questions asking him to explain the diary entries and identify whom in the DEA he told.

He issued a statement in which he said: "I did all in my power to ensure that when ever the slightest rumor or concern was raised about drugs, the matter was immediately referred to the cognizant authorities in our government."

But top law enforcement officials -- including the former heads of the DEA and U.S. Customs Service -- who met with North at the time on a variety of issues said in recent interviews that he did not pass the information on to them.

Former State Department, CIA and White House officials also say North did not tell them about the New Orleans plane. Nor, they said, did North tell them of other information -- relayed to him by the same aide in a memo -- about an aircraft and crew listed in law enforcement records as being suspected of drug trafficking. As a result, former State Department officials said, that plane and crew continued to be used as official carriers of U.S. government humanitarian supplies to the contras.

Many of these officials, when recently read the diary entries and memos, expressed surprise at how much North knew.

The diary entries are but a fragment of the Iran-contra affair, in which North and others secretly sold weapons to Iran to free American hostages, then diverted profits from those sales to a congressionally banned effort to arm the contras fighting the Marxist Sandinista government in Nicaragua.

In the campaign by Republican nominee North to unseat Sen. Charles S. Robb (D-Va.), a major issue has been character. Polls, and the candidates themselves, have repeatedly raised questions about Robb's honesty about his personal life and North's candor about the Iran-contra affair.

Drugs have been a minor but persistent theme. North has accused President Clinton of avoiding the war on drugs and reminded voters that Robb was present at Virginia Beach parties where drugs were used.

In his written statement Friday, North said, "It is a moral outrage and a cheap political dirty trick by desperate opponents, to even suggest that I or anyone in the Reagan Administration, in any way, shape or form, ever tolerated the trafficking of illegal substances or any such activities."

Drug-Trafficking Allegations

In 1979, the Marxist-led Sandinista National Liberation front toppled the dictatorship in Nicaragua. President Reagan authorized covert CIA support to the anti-Sandinista groups, or contras, two years later.

The same year, in an unrelated move, then-Marine Maj. Oliver L. North was detailed to the National Security Council staff. North worked on various projects -- among them counterterrorism and the Grenada invasion.

In 1984, Congress prohibited direct or indirect military support to the contras, and North became the administration's "point of contact" with the contras at the request, North said, of CIA Director William J. Casey and National Security Adviser Robert C. McFarlane.

In April 1986, published media reports said federal investigators were looking into possible illegal support for the contras, some of it financed by drug-smuggling. A Senate subcommittee chaired by Sen. John F. Kerry (D-Mass.) began looking into those allegations.

On Nov. 25, 1986, Reagan held a news conference in which he said he had not been fully informed about North's operations, specifically the diversion of profits from Iranian arms sale to the contras. He announced North's dismissal.

Two years later, the Kerry committee's final report concluded, "It is clear that individuals who provided support for the contras were involved in drug trafficking." A Kerry staff aide said the committee found evidence, including North's diary entries, that North knew about the trafficking.

Another subcommittee, chaired by Rep. William J. Hughes (D-N.J.), ran out of time and money before concluding its investigation, Hughes said, but "found that there were ties between the contras and drugs," though North's role was not completely investigated.

In his written statement Friday, North said, "Special Prosecutor Lawrence Walsh conducted a multi-million dollar, seven-year inquiry into every conceivable aspect of my life and never once made any such charge or allegation."

Sources close to the Walsh investigation said the fact that questions about drugs and North were not acted upon or fully explored was in no sense an exoneration. The prosecutors did not receive North's voluminous notebooks until he took the stand in his 1989 trial, which made questioning him about them difficult.

North ultimately was convicted of three felonies -- overturned on appeal -- but after his trial, the Walsh probe's focus shifted away from him.

Between 1984 and late 1986, when the alleged drug trafficking was occurring, there were many efforts to help the contras. During that period, North was trying to control those efforts. Some involved military supplies and were secret. One public effort was carried out by an agency created by Congress in 1985 called the Nicaraguan Humanitarian Assistance Office, or NHAO. Based in the State Department, its job was to get $27 million in strictly humanitarian supplies to the contras.

North flew occasionally to Central America for contra-related meetings, but for the most part, he kept track of the secret and public efforts from his office in the Old Executive Office Building with a bank of telephones, a computer and a spiral-bound notebook where he kept a daily diary.

North relied on Robert Owen, who traveled among Central America, Miami, New Orleans and Washington, to be his "eyes and ears," as North once described him.

A former staff member of Sen. Dan Quayle's and a fervent contra supporter, Owen worked for the contra leadership in 1984. He helped them, he said, "in any way I could," including bringing lists of needed arms to North and distributing money, provided to him by North, to contra leaders.

At North's urging, NHAO hired Owen as a contractor. By day, Owen worked on the humanitarian effort, and in his off-hours, unbeknownst to NHAO's director, Robert W. Duemling, Owen reported to North and helped with the secret weapons supply network.

Duemling said NHAO reported, as a practical matter, to a group whose key members were North, in the National Security Council; Elliott Abrams, assistant secretary of state for Latin American affairs; and Alan Fiers, chief of the CIA's Central American Task Force.

NHAO officials say they didn't know about North's covert weapon supply. They knew little about the contras' own effort to ship weapons with aircraft they leased or owned. They knew little of efforts of private citizens -- including exiled Cubans and paramilitary groups.

Owen's memos from the period are filled with details about all of the groups. He shared with North suspicions about some of the contra leaders' drug ties, political maneuvering among the groups, the contras' desperate need for arms.

Just before NHAO was up and running, after meeting with Owen on Aug. 9, 1985, North wrote in his diary: "Honduran DC-6 which is being used for runs out of New Orleans is probably being used for drug runs into U.S."

The information apparently stayed in North's mind, because the next day he wrote, "Meeting with A.C. --Name of DEA person in New Orleans re bust on Mario DC-6."

A.C. could be contra leader Adolfo Calero, brother of Mario, who was in charge of a warehouse and shipping operation for the contras in New Orleans. Pilots familiar with contra supply operations say Mario Calero regularly used a DC-6, based in Honduras, that made runs between New Orleans and Central America. Mario Calero is deceased.

The entry's references to a DEA person in New Orleans and a bust are cryptic. Local, state and federal law enforcement agencies, when asked by The Washington Post to search for any records of drug trafficking by Mario Calero, or by a company associated with him, say they could find none.

In a closed session before Congress in 1987, North testified that he reported to the DEA the information that the DC-6 might be making drug runs into the United States. In the session, which has since been declassified, North was read the entry, and responded: "It was a DC-6 registered in {name of country} and someone had told me -- in fact it was probably Rob Owen who told me that. I turned it over to the DEA immediately."

Jack Lawn, the former head of the DEA, talked to North on several occasions in 1985 and 1986, mostly about DEA informants in the Middle East. But "Ollie did not provide any intelligence to me" about the New Orleans tip, Lawn said.

Robert Bryden, then the DEA special agent in charge of the New Orleans office, said neither he nor anyone in his office ever received any drug information from North, the White House or anyone else concerning Mario Calero or any DC-6. Bryden said he would liked to have known.

"Our business is drugs, so if somebody knows about an airplane using drugs, we would like to know about it," Bryden said.

Former national security adviser McFarlane, North's boss at the time, said North did not relay the drug suspicions about the DC-6 to him.

"He never reported it to me," said McFarlane, who has harshly criticized North since their work together for Reagan. "He certainly should have reported anything which is a violation of U.S. law, which it sounds like that was."

William Von Raab, then head of U.S. Customs, said he is "absolutely stunned" by the North notebook entries. "I had dealings with North. I was a trusted conservative guy. While extremely law-abiding, I was on their side ideologically. He should have told me. Were any information like that available, as a courtesy, as a routine practice, he should have told me."

Former deputy CIA director Robert Gates also was surprised by the entries. He said he would expect anyone provided with such intelligence "to immediately go ballistic, to talk to Von Raab, to DEA. A normal person would have reacted strongly."

NHAO director Duemling and five other NHAO officials interviewed said North never alerted them to any concerns about Mario Calero or any aircraft of his associated with drug trafficking. "On the contrary, he wanted me to work with Mario," Duemling said.

A former ambassador and a career Foreign Service officer, Duemling admits he knew little about getting supplies to a rebel force in hostile territory, or about the contras. He said that he relied on North, as an expert on the contras, to guide him and that North instructed him not to disturb the contras' logistics arrangement.

Duemling said he believed North should have relayed to him the Owen leads about drug trafficking.

"I'm disturbed and disappointed that senior U.S. officials would be guilty of this kind of malfeasance," Duemling said.

"We're talking about the business of the U.S. government, about senior officials in the U.S. government. We're talking about the responsibility of implementing the foreign policy of the U.S. government. These are not things you should be playing games with."

Abrams, one of the three officials including North whom NHAO reported to, said he couldn't answer why North didn't tell Duemling, but said the drug allegations concerned "air charter companies and you're dealing with a lot of fly-by-night operations."

"It was really not easy to find out what was the last previous trip of that plane or what would happen to that plane when they were done with it," he said. "And legally speaking, that was none of our business."

He said that when he and North found out about two people in the contras' own organization who were suspected of drug trafficking, they were kicked out. Abrams would not name them on the record. "We had no proof, just rumors, and the rumors were enough for us to act," he said.

North's involvement with NHAO went beyond providing advice. Over time, North piggybacked his arms effort onto the publicly sanctioned humanitarian effort.

"It became fairly clear to me as time went on, by January {1986}, what was really happening was Ollie was hijacking the NHAO operation," Fiers testified in a 1992 trial.

That system, documented in numerous Iran-contra records, worked like this: NHAO aircraft loaded with humanitarian cargo flew from New Orleans and Miami to Ilopango Air Base in El Salvador, and sometimes Aguacate, Honduras.

There, humanitarian supplies were offloaded and stored. The NHAO planes then became part of North's secret operation and were loaded with military supplies for flights to contra camps in Honduras or for air drops into Nicaragua.

NHAO paid only for the humanitarian leg of the flights. The military leg was paid for from Swiss bank accounts North set up to finance the covert operations.

Another Owen Warning

Six months after Owen warned North about Mario Calero and the DC-6, he warned him about an NHAO contractor.

Owen's memo of Feb. 10, 1986, reads: "No doubt you know the DC-4 Foley got was used at one time to run drugs, and part of the crew had criminal records. Nice group the Boys choose. The company is also one that Mario has been involved with using in the past, only they had a quick name change. Incompetence reigns."

The only DC-4 listed in NHAO records was one supplied by Miami-based Vortex Air International Inc. One of the company's key officers, who is mentioned in North's diaries, has a long record of serious drug allegations.

In testimony to the Iran-contra committee about his DC-4 memo, Owen identified Foley as Pat Foley of Summit Aviation, which still operates in Middleton, Del. Owen identified "the Boys" as the CIA.

In a recent interview, Foley denied the implication in Owen's memo that he worked for the CIA, but agreed he gave NHAO a list of air cargo companies that could be hired, including Vortex. He said he was unaware of any drug allegations against the company.

Those drug connections surfaced when the DC-4 had engine trouble on an NHAO flight and had to land on San Andreas Island in Colombia, where it was detained. Colombian authorities had discovered that the plane was flagged in international law enforcement records as having been used to fly drugs and that some of the crew had criminal records.

Owen, who recounted that incident in testimony to the Iran-contra committee, said his concern was: "In my mind, it was stupidity to use a plane that at one time had been used, or at least targeted, as having carried drugs, and also it was stupidity to use people who had a criminal record."

Frank McNeil, then senior deputy assistant secretary of state for intelligence and research, confirmed Owen's account in an interview. According to McNeil, Colombian police contacted the U.S. Embassy in Colombia, and it cabled the State Department.

"We queried the CIA, and after they did some checking, they responded, something to the effect, 'It's unfortunate, but it's pretty hard to find folks to do this work,' " McNeil said recently.

McNeil would not reveal the identity of the CIA official involved. The emergency landing was suspicious, he said, because the island was a shipping point for drugs. After the Iran-contra investigations, McNeil learned the group had continued to supply the contras. "The whole thing is too sleazy for words," he said. "It is not a happy chapter in American history."

Owen's warnings about Vortex's drug problems didn't end its NHAO flights, and North's notebooks show that he was aware they were still working for the agency.

The name of Vortex, and one of its officers, who had numerous drug charges -- Michael Bernard Palmer -- appears twice.

The diary entries show North had detailed knowledge of Palmer and Vortex's NHAO flights. On April 22, 1986, North wrote: "Call from Rob. 900 Uniforms, 1800 Pr boots, 1700 ponchos, 1700 suspenders, SOX, belts, hats} Vortex/Miami."

Two days later, a second entry lists a Vortex flight's destination, the type of aircraft, identifying tail number, pilot, and departure and arrival times. It ends with Palmer's name and phone number.

During the congressional inquiries into the contra drug link, Palmer was an important witness. Under a grant of immunity in 1988, he testified that he flew for major drug organizations between 1977 and 1985, making frequent runs between Colombia and the United States.

Before Vortex's contract with NHAO, Palmer, himself a pilot, landed in a Colombian jail on drug charges, according to grand jury testimony in one of Palmer's later drug cases. He was released in Colombia under circumstances never fully explained.

Palmer was indicted in Detroit in June 1986 while Vortex was still under contract to NHAO. The Detroit indictment named Palmer in a conspiracy to import and distribute marijuana, beginning in 1977 and ending in June 1986.

In 1989, a federal indictment in Louisiana charged Palmer with helping to bring 300,000 pounds of marijuana into the United States from South America in a 1982 operation.

The Detroit prosecutors would not explain why that case was dropped. In the Louisiana case, Palmer boasted to prosecutors that his drug running was sanctioned by the government, and the prosecutor, Howard Parker, said he dropped the charges to avoid a sideshow.

The idea that Palmer worked secretly for a government agency, even after his NHAO contract was over, is supported by declassified Customs records. The documents, supplied to congressional committees looking into alleged contra drug ties, show Palmer was working in 1987 for a government agency, the name of which was blacked out.

The records describe an incident in which Palmer protested a Customs inspection of a DC-6 that Vortex was servicing at Miami International Airport. The records say: "Normal U.S. Customs Service procedures for incoming flights are expedited" at the request of the unnamed agency.

The unnamed agency's officials knew of the open drug charges against Palmer, but "our records do not go beyond allegations, the substance of which did not preclude us from using these individuals," the Customs records state.

Palmer said in a recent interview that he didn't know North. The drug cases were dropped, he said, because he was not guilty of the charges.

Vortex was not the only company used by NHAO with an officer accused of drug trafficking.

During the time NHAO was operating and hiring air cargo companies, Duemling and NHAO's attorney said they requested background information from the Justice Department about the NHAO contractors, but never received a reply.

It wasn't until after NHAO had closed down, when Sen. Kerry's subcommittee published its report, that it became clear that several cargo carriers and suppliers NHAO had used were either owned or operated by individuals under investigation by federal law enforcement for drug trafficking.

In addition to Vortex, the report listed DIACSA, based in Miami. DIACSA received $41,120 in NHAO work; Vortex received $317,425. Two foreign firms were listed in the report: SETCO Air, a Honduran company, and Frigorificos de Puntarenas, a Costa Rican firm.

DIACSA's owner, Alfredo Caballero, and Floyd Carlton, who ran a drug and money laundering operation out of DIACSA's Miami offices, according to DEA affidavits, were under indictment at the time of the NHAO contract. Carlton pleaded guilty to a cocaine trafficking charge. Caballero was indicted in a cocaine conspiracy and pleaded guilty to one count, but the specifics of the plea are sealed. Carlton later became the star government witness in the drug trial of Manuel Noriega.