A tawdry picture is emerging on Capitol Hill of an operation that the key participants have described as a patriotic cause: the secret effort to support the Nicaraguan rebels when U.S. military aid was prohibited.

In four weeks of testimony before the House and Senate panels investigating the Iran-contra affair, the men who planned and managed the clandestine resupply of the contras have told -- while under oath -- conflicting stories about the same events. They have accused each other of profiteering, attempted theft, security breaches and even of leaking information to left-wing news media.

One witness who worked for the private airlift did not disagree last week when Sen. Warren B. Rudman (R-N.H.), vice chairman of the Senate committee, described the operators of that airlift in some of the most lurid terms heard to date: "So, they were not only arms dealers, but they were making fifty to sixty thousand dollars on people who were risking their lives. So they were arms dealers, and they were also flesh peddlers, were they not, Mr. Rodriguez?"

"It would look like {that} with this paper, sir," answered Felix Rodriguez, a former CIA employe who began working with the secret airlift operation supporting the contras in September 1985, but soon became disgruntled.

One explanation for the conflicts and contradictions in the testimony may be simply that some witnesses are trying to cover up possible illegalities. But it is also evident from the conflicting stories being told by key participants that some are using their moment in the spotlight to rationalize their own actions, or continue old feuds.

When the contra support operation was a closely held secret within the Reagan administration, the intrigues and clashes of participants were far from public view. Now that the story is out in the open, past frictions that once handicapped the operation itself are being exposed.

Retired Air Force colonel Robert C. Dutton last week described Rodriguez as a "detriment" to the airlift operation who had used his influence with the Salvadoran military to make life difficult for Dutton and others. Dutton said he believed Rodriguez was motivated by "money" -- specifically a desire to get control of a special emergency fund and "fuel account."

Dutton said there was concern within the operation that Rodriguez was "feeding information" to journalists involved in a lawsuit against Dutton's bosses: former National Security Council aide Oliver L. North Jr. and retired major general Richard V. Secord.

But Rodriguez, who introduced himself to the committee members as the only foreigner who was able to talk to Cuban revolutionary Ernesto (Che) Guevara for approximately two hours before he died from bullet wounds after his capture in Bolivia in 1967, turned the tables. He said he had placed an armed contra guard on Secord's planes to prevent them from being "stolen from the contras."

Under questioning, Rodriguez acknowledged that another of his allegations -- that arms suppliers had charged the contras $9 each for hand grenades that could be obtained for $3.50 -- had come from an arms dealer whose company was competing for business with the Nicaraguan rebels.

Key witnesses frequently have given different versions of the same event.

Testifying on the first day of the hearings, for example, Secord told of an all-night meeting in July 1985 in Miami at which North warned that limited contra funds might be "getting wasted, squandered, or even worse -- some people might be lining their pockets."

The message, Secord said, was directed at the two top contra leaders present: Adolfo Calero and Enrique Bermudez. North, Secord continued, was raising the corruption issue as part of a broader plan to reduce Calero's role, set up the U.S.-run airlift in Central America and strengthen southern forces not under Calero's direct control.

But when Calero told the House and Senate committees of the same meeting two weeks later, he said he recalled no discussion of corruption in the ranks of his Nicaraguan resistance group.

"No, in much less the way that Gen. Secord put it, because I would have been very upset by something like that," he said. "No, I don't remember that."

Calero also specifically denied Secord's assertion that there had been a discussion of an airlift, much less the "common agreement" that Secord said had been reached on the need for it.

In the wake of the Miami meeting, Secord, at North's direction, began to put together a clandestine enterprise to obtain planes, hire crews, and build runways. Blocked by the Honduran government from establishing their main base of operation there, North and Secord sought to locate in El Salvador.

To assist in this politically delicate matter, North secretly turned to Rodriguez, who had established useful high-level contacts while serving as an adviser on guerrilla warfare.

On Sept. 20, 1985, North sent Rodriguez a letter asking for him to get Salvadoran approval for landings by Secord's supply planes at the Ilopango military base. Once approval was obtained, North said, a "Mr. Green" would arrive to coordinate the operation.

Rodriguez testified that within a day or so of receiving the letter, he called North and "told him it was a go." Mr. Green, he added, arrived in mid-December 1985 and turned out to be an old Central Intelligence Agency comrade, Rafael Quintero, with whom Rodriguez had had a falling out.

The situation was tailor-made for friction. Rodriguez was a former CIA operative with powerful local friends, and as he often told American acquaintances, friends in Washington high places as well. His room in a Salvador house was said by an eyewitness to have had three pictures of him with Vice President Bush.

With the arrival of Mr. Green, however, Rodriquez found himself being elbowed aside by the distant figures of North and Secord.

In Secord's version of how the airlift began, however, the Rodriguez role was considerably diminished.

It was his man Quintero, he said, who went to El Salvador "and negotiated with the local military and with an old friend of his {Rodriguez} who was working there and got an agreement in principle about this timeframe, that is the fall of '85, for the basing of a small airlift operation." Secord acknowledged that Rodriquez had been "very, very helpful in helping establish the operational base" and "acting as a liaison with the local authorities in the early months of this operation."

Over time, Secord said, Rodriquez "became more of a problem for us because he voiced all kinds of dissatisfaction with the overall operation . . . . He said that we were profiteering at the contras' expense. Of course he didn't know, he didn't understand how this business was being run at all. And he thought that the contras were given this money for this operation, which of course, they were not."

The Secord enterprise that supported the airlift was financed by tax-exempt donations and funds diverted from the sale of U.S. arms to Iran, Secord testified. But because it was secret, oversight and accountability were minimal.

Since testifying, Secord repeatedly has denied assertions that he "profiteered," but that charge was made again last week by Rudman, who said Secord and his business partner Albert A. Hakim were "beneficial owners" of East, Inc., which billed the airlift project for 31 days of a pilot's services in March 1986 at a rate of $450 a day. Committee sources said the actual rate was $150 a day.

The conflict surrounding the secret effort on behalf of the Nicaraguan rebels appears to have been political as well as monetary.

Testimony and documents introduced about the March 1986 visit of retired U.S. Army major general John K. Singlaub to Costa Rica, for example, have raised puzzling questions that may be answered when Assistant Secretary of State Elliott Abrams testifies starting Tuesday.

Singlaub, a crusty, inspirational adviser to anti-communist resistance movements around the world, made the trip at the urging of Sen. Jesse Helms (R-N.C.) in an effort to bring contra leader Eden Pastora into the cooperative framework of the Nicaraguan resistance.

Singlaub testified that he spoke to Abrams before setting off on this mission and "while he {Abrams} expressed some doubts that it could be done," the assistant secretary "posed no objections."

In fact, Pastora was at that time being dropped by the CIA with the support of North and Abrams, who considered him uncontrollable, according to other sources. A typewritten notation added at the State Department to a telegram introduced at last week's hearings indicated another concern: " 'Popo' Chamorro {a contra commandante close to Pastora} is alleged to be involved in drug trafficking." At the time, a source said, the U.S. government had received information that Chamorro may have been involved in a narcotics deal.

Lewis A. Tambs, who was then U.S. ambassador in Costa Rica, testified that he arranged an unclassified briefing with the CIA station chief for Singlaub, an old friend. Tambs testified that when he got word Singlaub "had gone up to the San Juan River" to meet with Pastora, he arranged to have dinner with him so he could report back to Washington "to keep them in touch."

Tambs portrayed himself as a neutral, who simply "reported" on the Singlaub mission. But the "back channel" cable that Tambs dispatched to Abrams and North through a CIA means, and which was presented to Tambs at the hearing Thursday, suggests more active involvement.

It reports that Singlaub called Tambs on March 25, 1986, and arranged for a meeting the next morning at the embassy. In describing that session, the cable said that "it was agreed that if Singlaub could obtain Pastora's written agreement to meet certain conditions, Pastora should receive supplies via UNO {the United Nicaraguan Organization}."

Later that same day, according to the text of the telegram, Singlaub and Pastora signed an agreement committing the United States to provide "boots, food, ammunition, medicine, maps, encrypted communications systems and military needs for Pastora's troops including new men who join his army." In return, Pastora was to lead his troops into Nicaragua and cooperate with other elements of the Nicaraguan resistance.

Abrams responded to the news of the agreement received through the back channel with a highly critical "rocket" chastising Tambs for getting the United States involved and expressing "astonishment" that Tambs could have involved himself in an agreement that purports to commit the United States to provide military materiel to Pastora. The Abrams telegram noted that Tambs' role, during the ban on U.S. military aid to the contras, "might also raise legal questions."

Tambs was not asked why, in his opinion, Abrams had responded with such on-the-record anger, in light of the fact that Singlaub testified he told Abrams of his plans only a few days earlier.