When gunmen killed union officials Silme Domingo and Gene Viernes in their Seattle office two years ago, many concluded that it was just another violent episode in the corruption-ridden history of Local 37 of the Alaska Cannery Workers' Union.

But now, the slayings of the two 29-year-old Filipino-Americans are a cause celebre among some Filipino exiles and dissidents in this country who contend that the two were murdered because of their active opposition to Philippine President Ferdinand Marcos.

Last September the slain men's relatives and friends, who formed the "Committee for Justice for Domingo and Viernes," filed suit against the U.S. and Philippine governments in federal court in Seattle, alleging that Philippine agents conspired to violate the civil rights of the two men, an action which eventually resulted in their deaths, and then with the complicity of U.S. officials tried to cover up the plot.

The suit asks millions of dollars in damages for the families and injunctive relief from harassment for Filipino dissidents in this country.

When asked for evidence of U.S. involvement in the murders or a cover-up of them committee officials are not specific but say they have unearthed some puzzling incidents. The most notable were three telephone calls that Local 37 President Constantine Tony Baruso allegedly placed to the State Department within 24 hours of the killings.

Baruso, a Filipino-American who supports Marcos, was questioned by police in connection with the murders for which three other men have been convicted. Prosecutors said there was not enough evidence to charge Baruso.

Committee members said that they suspect Baruso has links to the Philippine government and U.S. intelligence agencies, and that he is being protected for that reason.

Asking dismissal of the suit, U.S. attorneys charged that "stripped of its sweeping allegations, the complaint is, at most, a vehicle to invoke the forum of the federal courts to air a vigorous opposition to the current government of the Republic of the Philippines and to the harmonious relations that our nation shares with that government."

The Philippines is one of the closest allies the United States has in southeast Asia. In June the governments of the two countries renewed an agreement that will give the Philippines $900 million over the next five years in exchange for the United States' use of Clark Air Base and Subic Bay Naval Base, the most important U.S. military bases in that part of the Pacific.

Committtee members said they believe that if the suit, which is still in the pre-trial motion stage, proceeds it will reveal that the Philippine government was involved in the two deaths and that the U.S. government assisted in covering up that fact. Such revelations could encourage criticism in this country of the ties Washington has with Marcos.

The committee has informed the court that it will provide the names of Philippine government officials who participated in the alleged murder plot as well as dates and locations of alleged meetings between them and Baruso.

It also told the court it will supplement the suit with allegations showing U.S. officials' involvement in "the cover up of the murders, in particular the protection of Tony Baruso from prosecution for his role in the murders," and their role in watching Viernes on a trip to the Philippines shortly before his death as well as in providing intelligence on Domingo and Viernes to named Philippine defendants.

To bolster its case, the committee has documents obtained under the Freedom of Information Act from U.S. Naval Intelligence and the FBI that show that activities of Filipino dissidents in this country were under surveillance in the early 1970s.

The committee also cites a 1979 classified report prepared for the Senate Foreign Relations Committee that states that U.S. intelligence authorities were aware that Filipino agents were spying on Filipino dissidents in this country.

A Defense Intelligence Agency circular dated July 23, 1982, indicates U.S. officials were aware of such activity by Filipino agents then. The circular contained biographies of a five-man defense attache team posted to the Phillipine Embassy in Washington last year.

"The new team is also expected to monitor Philippine dissident activity in the U.S. . . . The attaches will undoubtedly report on, and possibly operate against, anti-Marcos Philippine activists in the U.S.," the circular said.

In 1981, Congress passed an amendment to the Arms Export Control Act that prohibited military assistance to any country "determined by the president to be engaged in a consistent pattern of acts of intimidation or harassment directed against individuals in the U.S."

The activities of Filipino dissidents in this country may be disturbing to Marcos, who seems to pride himself on his close relationship to Washington.

Filipino-dissident groups have varying political stripes. Among the most active is one that helped set up the committee and is active in the "Coalition Against the Marcos Dictatorship," which lobbies in Washington against Marcos.

Some members of both groups belong to the Union of Democratic Filipinos (KDP), a United States-based coalition of leftist groups. Although it supports a communist guerrilla movement in the Philippines known as the New People's Army, KDP members say their organization is not a communist party.

Domingo, a Phi Beta Kappa graduate of the University of Washington, was active in the Seattle chapter of the KDP.

Members of the committee provided the following outline of the events that led to the murders:

In 1980 Domingo and Viernes organized a "reform" movement within Local 37 to root out the corruption, extortion and bribery that had long plagued the union, which is made up largely of Filipino-Americans working in the Alaskan salmon canneries.

The movement won most of the union's top positions, but failed to oust Baruso from the presidency. Domingo became dispatcher and Viernes secretary-treasurer.

In March, 1981, the American-born Viernes made his first trip to the Philippines and contacted the May First Movement (KMU), an independent trade organization critical of Marcos.

Viernes left the Philippines with a KMU request for the support of American labor groups. In Honolulu, he joined a Local 37 delegation, which included Domingo and Baruso, at the International Longshoremen's and Warehousemen's Union (ILWU) convention.

Domingo and Viernes drafted a resolution calling for the ILWU to send a team to Philippines to investigate the labor situation there. The resolution passed.

Six weeks later they were murdered.

Three Filipino-Americans were convicted of the murders. As he stumbled into the street, the fatally wounded Domingo had named two of them to a rescue-squad firefighter.

At the trials, prosecutors linked the slayings to gambling and unhappiness over the Local 37 changes initiated by the two activists.

Baruso and Teodorico (Boy Pilay) Dominguez were questioned by police in connection with the murders but were not charged.

The committee cites circumstantial evidence linking Baruso to the murders, including the fact that he owned the gun used in the crime. (Baruso said his gun was stolen from his car before the murder, though he never filed a stolen gun report with the police.)

The committee also said that Baruso exercised his Fifth Amendment rights more than 100 times in response to questions from defense attorneys and prosecutors during the trials of the three men convicted of the murders.

It also points out that one witness at the trials testified that Dominguez had told him he had been in on the murders. Months later, the committee discovered a person from the Washington, D.C., area who signed a sworn affidavit that Dominguez had said that Baruso had put out a contract for the two men and promised Dominguez $5,000 to kill them.

Early this year the committee asked Baruso in a deposition for a civil suit about allegations that he had made calls of 11, seven and three minutes to unidentified persons at the State Department within 24 hours of the killings. Baruso said he did not recall calling the State Department.

Two days later, Dominguez was murdered in an execution-style shooting. Police charged two men with the slaying, and said it was motivated by revenge for another killing and had nothing to do with the Domingo-Viernes murders.

But Domingo's widow, Terri Mast, disputes that theory.

"Our feeling was that Pilay Dominguez was the only one left who could point the finger to Baruso," she said. "It certainly was very coincidental."

Baruso has since been recalled as president of Local 37 and replaced by Mast. The union has charged Baruso with double-dipping into its funds and has filed suit to regain several thousand dollars it alleges he stole. Baruso denies the charges.

In the committee suit, U.S. District Court Judge Donald S. Voorhees has given U.S. officials immunity from any monetary claims. But he has denied two U.S. government motions requesting dismissal of the suit and immunity for U.S. officials who are "engaged in this sensitive function of conducting foreign affairs" on the grounds of "national interest."

Voorhees also found that, as foreign sovereigns, Marcos and his wife, Imelda, are immune from suits. In July he dismissed claims against the Philippine government but said the committee may amend its allegations to make them more specific.

The committee said that it would ask Voorhees to reconsider his dismissal of the claims against the Philippine government. Regarding the option of amending its allegations of Philippine and U.S. involvement in the conspiracy, the committee said, "This we will have no difficulty doing. Since the complaint was filed last September, additional information has come to light which thoroughly implicates the U.S. government in the conspiracy against the anti-Marcos opposition."

A spokesman for the Justice Department said that the department is still studying Voorhees' latest rulings.

Since the murders, skepticism has grown that gambling and intramural union rivalry explain them.

One of the men convicted of the murders said that he knows who ordered them but is afraid to say because he fears that his children, who live in the Philippines, will be harmed. His lawyer, John Henry Brown, said, "I was skeptical of wild accusations about a conspiracy in this case, but not any longer."