At mid-afternoon on Nov. 2 high over the South Atlantic, the twin-engined Piper Navajo packed with 1,450 pounds of marijuana was nearly out of fuel. The pilot, Ed Binion, an undercover informant for the U.S. Customs Service, was 15 minutes short of his drop zone south of Bimini Island.

He banked the airplane at 10,500 feet and discussed the options with 69-year-old copilot Emory Amos. Binion knew he could glide to the drop zone and kick the bales out to the waiting boats of the Miami-based smuggler running the operation. But that would require ditching a $90,000 aircraft. That is when he noticed a Customs Service chase plane tucked in 100 feet under his tail.

Binion was not worried, he said, because his customs control agent in Miami had told him if he got into trouble he would be protected in any country except Colombia. The decision was easy. They would keep the marijuana on board, fly into Nassau airport, refuel and ask the customs agent in the chase plane to check with their Miami control agent so he could clear them with Bahamian authorities. Then they could take off quickly and deliver their load. That is when things began to go haywire for Binion and Amos.

Their trip now stands at the center of a controversy in the murky world of South Florida drug enforcers and informants: Did a seasoned drug task force agent commit a serious breach of confidence or was a professional informant trying to pull off an ingenious plan to smuggle marijuana under the noses of his keepers?

On the ground in Nassau, Binion told Bahamian officials that he was working with a senior Customs Service agent of the South Florida drug task force. He gave the name of the agent, Darryl Archer, and his Miami telephone number to the customs pilot who had followed them into Nassau.

After a few minutes, the pilot reported that Archer knew the men, but he had denied giving them authorization for the flight.

Hearing that message from Archer, the man Binion had worked and consulted with on virtually a daily basis since Oct. 4, "was like smacking me with a ball bat," Binion said.

Within hours, Binion and Amos were booked, fingerprinted, stripped, searched and locked in a 9-by-12-foot cell in the Nassau jail where the concrete floor was their bed and a water pail their sanitation. Binion made his $10,000 bail in three days. Amos was not released for two weeks.

What began as a lucrative arrangement in which Binion and his partners would reap a large bounty for supplying airplanes to smugglers, and information about them to the drug task force, has ended in accusations of bad faith and betrayal on both sides. The only early consensus among federal officials seemed to be that Amos was an innocent victim caught in disputed circumstances.

Customs Service officials, whose agency joined the FBI and Drug Enforcement Administration (DEA) to form the task force in January, say they are anxious to sort out the truth in this case because their reputation in the informant community and public image are at stake. The case highlights the difficult relationships entered into by drug investigators and professional undercover informants.

Archer was not available for comment, but has said in interviews with task force investigators that he worked with Binion, Amos and others to set up an undercover operation during October. He also said, however, that on the eve of Binion's and Amos' flight, he telephoned and forbade Binion to go.

Binion meanwhile has mustered five witnesses, two of them law enforcement officials, to help corroborate his version of events.

If the informant's claim he was betrayed is true, the task force may have blown the cover and endangered the lives of some valued undercover assets described by one senior official as "very credible and known informants who have been used efficiently in the past by the FBI, the DEA and customs."

If the customs agent's claim is upheld, the service may have to take a second look at its operations to determine how easy it is for professional informants to play both ends, cashing in on government bounties while moonlighting, with relative impunity, as drug runners.

The relationship that promised something for everyone began in the drab offices of an assistant U.S. attorney in Miami's downtown federal building on Monday Oct. 4. Leslie Edward Binion, 48, had been subpoenaed to testify in another drug case.

He flew down the night before from his Portland, Tenn., home, picked up his informant partner, Joseph Hamilton, 41, in Atlanta and introduced himself to the federal prosecutor who had invited customs agent Archer to sit in on the meeting.

They discussed Binion's role in the drug case coming to trial and Binion revealed his undercover credentials to the prosecutor and invited him to check them out. At the end, Archer said he was interested in talking to Binion about how he might assist the South Florida drug task force. It was agreed that Archer would drop by for drinks later that day at the Brickell Point Holiday Inn, where Binion and Hamilton were staying.

According to the two men, Archer made this proposition: they should go into the aircraft-leasing business, renting planes to suspected smugglers and providing information about them to the task force. They would be able to charge the smugglers from $15,000 to $20,000 on the front end of deals and, in return for information, the task force would pay them "up to $50,000" on the back end of any deal where arrests were made and contraband seized. Archer also pledged that the planes would never be seized, both men said.

"We could keep five or six planes busy that way," said Binion, a former car dealer. He added that he'd had a spate of bad luck in his first 18 months as a professional informant and "that's the reason it looked so good."

Binion and Hamilton began searching for planes. They said they held almost daily meetings with Archer or kept in daily telephone contact.

By mid-October, Binion said he found himself being courted by a major drug smuggling figure in Miami to bring in a small planeload of marijuana from Colombia. The identity of the smuggler -- still a target of investigators -- was confirmed by federal officials.

The smuggler needed to move quickly, according to Binion. He had sent a DC6 to Colombia some weeks before only to find that members of his smuggling syndicate had refused to load the plane until the Miami man paid off an outstanding balance created by several failed shipments. He needed a quick $100,000 to clear his accounts, he said. Binion relayed this information to Archer and the customs agent worked with Binion and Hamilton, the two men said, to locate an airplane to fit the smuggler's bill.

On Oct. 20, Hamilton sought out another of his law enforcement contacts, this one in Alabama. Lt. I.N. Bradford, deputy commander of the narcotics division of the Alabama Bureau of Investigation, recalled the conversation in an interview. "They were looking for a small plane, twin-engine aircraft. They told me they needed to run one small load in and then they would bring in a big load. They mentioned bringing a DC6 into Alabama. Of course, that was my interest in it."

Before Bradford would check his network of sources for available planes, he wanted an assurance that the plane would not be confiscated. He said he insisted on speaking with Archer to confirm Hamilton's claim that they were working with the Customs Service. Bradford made a note of the telephone call and took one other precaution.

"When I was on the phone with him Archer , I had another one of my agents on the extension . . . because I don't know Archer," Bradford said. "I'm not saying this deal is the deal that Archer was aware of, but he Archer was aware they were going to do a deal like this, he talked to me about it, they all explained it to me on the phone."

Bradford was not able to find a plane in time for the trip. But the man who did, Buford Lane of Portland, Tenn., said he also insisted on talking with Archer. Lane, a hometown friend of Binion's, recalled his Oct. 26 telephone conversation with Archer. "We're going to run a little scam," he quoted Archer as saying. "We're going to take this plane and haul marijuana. We'll do that a time or two and then we'll bust the smugglers. I'll guarantee that the plane will not be confiscated."

Lane put up $90,000 for the Piper Navajo that was purchased on Oct. 28 from Air Charter Travel in Adairville, Ky. Amos, an employe of the charter service who had never met Binion, was hired as copilot because Binion did not have enough hours logged on a Navajo to satisfy insurance requirements. "Nothing was mentioned about the destination," Amos said.

When they arrived at Miami International Airport at 6:30 p.m., the smuggler picked them up in a Lincoln Continental and drove them to the Holiday Inn. While Amos paced the hotel grounds, Binion and Hamilton made preparations for the flight, still communicating with Archer, they said, as they outfitted the Piper with a 40-gallon fuel bladder to extend range.

The smuggler was to have provided his own pilot. But on Saturday Oct. 30 he asked Binion to fly the plane. Binion said he immediately called Archer and reported the development. "The only thing he [Archer] wanted to know was where we were going, when we'd be back and where the drop zone was. He said, 'I can clear you everywhere except Colombia. If you get caught down there, you're on your own.' "

In the hotel room that afternoon, Binion said he showed Archer the drop zone on an ocean chart provided by the smuggler. It was a patch of turquoise water called Orange Cay, 45 miles south of Bimini. Binion, needing a copilot for the trip, came clean with Amos. Would he fly a load of marijuana in an undercover operation? "I told him I wouldn't do it," Amos said, "and he said, 'What if you were 90 percent sure nothing would go wrong?' " Saturday evening, Binion and Amos said they met Archer in the hotel lounge and that he showed the older man his U.S. Customs credentials.

Later, they drove in Archer's car to the East Coast Fisheries Restaurant, Amos said. "We parked across the street from the seafood place and Mr. Archer asked me if I wouldn't go along with Binion and I told Mr. Archer that I had an 18-year-old son who was smoking marijuana and it killed my soul to see it and if I could help get any of that stuff off the streets, I'd gladly go.

"He [Archer] had full knowledge of what we were going to do and gave us his blessing and then took us back to the hotel," Amos said.

Archer's account differs at this crucial point, officials said. Archer has told his superiors that he called off the flight that Saturday night in a telephone call, presumably to Binion, who denies it.

The flight took off at 7:30 a.m. the next morning and encountered problems with the fuel bladder. After a layover in Haiti, the plane arrived in a remote section on the northeastern Colombian coast, was loaded, refueled and took off after a weather delay on Tuesday, Nov. 2. By the end of the afternoon, Binion and Amos were in jail.

The task force officials and the Customs Service still have to reach a conclusion after dozens of hours of witness interviews. Referring to Amos' plight, one official said, "Right now we don't look so good." Diplomatic efforts were under way to release him from jail when his wife finally raised the $10,000 bail by mortgaging the family home.

Binion and Hamilton said they are out well over $100,000 through confiscation of the plane, bail expenses and lost revenues. When Binion was returned to Miami from Nassau, he said he telephoned Archer to confront him. "I got on the telephone and he started laughing. He said, 'You really screwed up,' and I said, 'You were supposed to have me covered.' "