The White House is deeply worried about what may leak out of a rare close Senate session that will be held Tuesday to consider allegations linking Panamanian leader Omar Torrijos to the narcotic trade.

The Senate session was called by Sen. Robert Dole (R-Kan.), a leading opponent of ratification of the Panama Canal treaties, after he received six classified documents that he said contain "certain allegations" connecting Torrijos and drug trafficking.

The allegations relate directly to the treaties, Dole said, because "if, in fact (they) are true and there is some drug trafficking by Torrijos, can he be trusted as a guarantor of the treaties?"

At Tuesday's session, the Senate Intelligence Committee will report on thousands of pages of classified documents, spanning a 10-year period, some of which White House sources said appear to be "terribly damaging on their face" to Torrijos.

The White House fears that once the documents are discussed before the full Senate, treaty opponents may selectively leak the most damaging allegations in hope of gaining support for their effort to block the treaties.

In a report to the Senate Foreign Relations Committee, the intelligence panel said it concluded from its study of the documents that the treaty negotiations were in no way affected by the drug issue.

But the White House officials said that the allegations in the files - made by informants, drug pushers and narcotic agents - are largely substantiated and based on second and third-hand information.

Many of the charges, they say, may well be libelous of Torrijos.

While the files contain numerous mentions of Torrijos and members of his family and government, the Justice Department has said that the Panamanian leader was never the "target" of an investigation.

Beyond that, the Carter Administration would be hard put to rebut the allegations against Torrijos, sources said, because in order to do so, it would have to expose intelligence sources and possibly refer to court-held information it does not have the power to make it public.

Among the documents now held by the Intelligence Committee, sources said, are the six that Dole said "just ended up on my desk" from an unknown source. The Washington Post has had access to two of those documents, both of which are based on Drug Enforcement Administration field agent reports.

The first, a 1974 document from the DEA office in Costa Rica, concerns a Costa Rican businessman and forner government official allegedly involved in cocaine trafficking. One informant said this Costa Rican businessman was "very closely related to Gen. omar Torrijos, the Panaamanina Head of State."

The informant, whom the DEA described as of "average reliability," said he believed that the businessman worked "with and for" Torrijos, and that between the two of them, they control the contraband traffic - primarily liquor and appliances - from the Panamaian duty-free zone.

A second informant rates "unreliable" by the DEA, said he had "no specific information relating (the businessman) to narcotics," but that the extent of the man's wealth made it hard to believe he made his money only through contraband or through legitimate activities in the five-page report, Torrijo's name is mentioned four times.

The second document, a 1975 report from the DEA field office in Santiago, Chile, concerns DEA attempts to infiltrate a cocaine smuggling ring in Argentina. The Torrijos name is mentioned once, when a drug trafficker tells the undercover agent that he has a contact who would purchase large quantities of cocaine in Panama. The contact, he says, "is the brother or brother-in-law of Omar Torrijos, the strong man in the Panamanian government."

According to White House and DEA officials, the allegations made directly against Torrijos in the first report were never corroborated by other sources or agents, and thus never led to a full-scale investigation. Yet, administration sources complained the information remains on file where it can be dragged out and presented out of context.

The DEA, one White House source said, is "just like the FBI. They never clean this stuff out."

Dole does not dispute the fact that Torrijos has never been the "target" of an investigation. But, he asks, "should he have been a target of investigation?"

"If some of the allegation set forth in some of the documents are true, though I have been cautioned many are bases on hearsay, why was he not a target of an investigation?" Dole asks.

The implication has been that the U.S. government always chose not to investigate Torrijos, despite frequent association of his name with narcotics traffic, because of foreign policy considerations.

These same considerations, treaty opponents now charge, make the Carter administration hesitant to tell the whole story.

While Panama is not a direct source of cocaine and heroin, it is a major transit point on the Latin American drug trail.

Allegations that Panamanian officials were involved in this licrative traffic even preceded Torrijos' rise to power in the military coup in 1968.

Despite literally hundreds of references in the intelligence documents to Torrijos and members of his family and government, only one Panamanina official and one Torrijos relative have ever been the subject of U.S. narcotics indictments.

The first date occurred in 1971, when a Panamanina air traffic controller was arrested in the U.S.-controlled Canal Zone on charges of conspiracy to traffic of cocaine. He was subsequently convicted by a court in Texas.

The secind potentially and far more damaging case likely to affect the treaties involves Torrijos' brother, Moises. In July 1971, 154 pounds of heroin was siezed from two Panamanians at New York's John F. Kennedy airport. three Panamanians and two Argentines were subsequently indicted in the case, and investigation also led to a sealed federal indictment against Moises.

Both cases were investigated in Panama by undercover U.S. drug agents. The failure of the U.S. agents to cooperate with Panamanian authorities led to the 1972 expulsion of the U.S. drug agents in Panama for their alleged "interference" in internal affairs.

In June 1972, John Ingersoll, then head of DEA's predecessor agency, visited Torrijos in Panama to smooth over the situation, reestablish a U.S. narcotics office there, and inform Torrijos that a secret indictment had been issued against his brother.

Torrijos says he asked Ingersoll to provide him with information about his brother's alleged crimes. According to DEA sources, Torrijos was not given that information because under court rules, evidence used in obtaining a sealed indictment is also sealed.

But another rreason, DEA sources acknowledged and Panamanian sources confirmed, was the belief that Torrijos would not move against his brother Moises while their mother was still alive.

Instead, sources disclosed that Torrijos and Ingersoll reached an agreement that was intended to avoid prolems with Moises and a diplomatic incident.

Torrijos agreed to make sure that Moises, who was then ambassador to Argentina and is now Panamanian ambassador toSpain, would have no involvement with the drug business, and would never again set foot in the United States or the Canal Zone. In return, the matter of the indictment would not be pursued.

While White House sources say "there is some stuff" in the files which reflects on Omar Torrijos, they say there was never any hard evidence to connect Torrijos directly to the drug trade.

"There is a fine line between participation and knowledge," said a DEA source.

There has been little mention of Torrijos in DEA files for the past two years, and cooperation between U.S. and Panamanina drug authorities has greatly increased.

An aide to Dole said yesterday that the senator is interested only in seeing the drug files, checking on whether the documents he has are included in them, and comfirming that the charges are adequately investigated.

To defuse the controversy and head off the selective leaking of allegations, the White House and the Senate Intelligence Committee met this weekend to try to draft a disclosure report for release on Tuesday.

One problem in preparing such a report is that all the documents on which the conclusions are based would have to be declassified. So far, intelligence agencies have been unable to agree on what reports can be declassified.