The Federal Bureau of Investigation is embroiled in a new controversy triggered by charges that a paid bureau informer was responsible for some of the bloodiest moments in the Ku Klux Klan's war against racial integration in the 1960s.

News reports this week have portrayed Gary Thomas Rowe Jr., the FBI's chief spy within the Klan from 1960-66, as an agent provocateur who personally shot civil rights demonstrators in Alabama and as a suspect in the bombing of a black church in Birmingham.

One account suggested that it was Rowe who fired the bullet that killed civil rights worker Viola Liuzzo after the freedom march on Selma, Ala., in 1965. Another said that Rowe admitted to the FBI that he had killed a black man with a gunshot in 1963 - and was told by the bureau to keep quiet about it.

The FBI issued a statement yesterday saying its files contain no information to substantiate the recent charges against Rowe.

The bureau said "Rowe was constantly advised by his case agent to avoid violence and to contact the FBI when he thought violence might occur. The FBI has no information to indicate that Rowe was involved in the crimes . . ."

Rowe, who left Alabama for a new life under a new name in California, could not be found to discuss the charges yesterday. He was not always reticent about his past, however. In 1976, he published a book about his life as an FBI undercover man, and acquaintances say he has been trying to sell movie rights to it.

Rowe was 29, the unemployed father of four, when the FBI recruited him in 1960 to infiltrate the Klan in Birmingham. The bureau paid him small sums at first, but by 1965, he later testified, he was receiving about $300 a month to keep the FBI informed about Klan members and their plans.

Rowe was on or near the scene of some of the bloodiest confrontations of the civil rights movement in the South.

He was present when whites beat Freedom Riders in Birmingham in 1961. He was riding in the car from which Liuzzo was shot on a road outside Selma. An associate of his in the Klan, Robert Chambliss, was convicted last year of the 1963 bombing of Birmingham's 16th Street Baptist Church that killed four black children.

There has always been speculation about Rowe's personal involvement in these events. The questions arose anew last fall when Alabama authorities used lie-detector tests to see if he would be a reliable witness for the Chambliss prosecution.

Alabama Attorney General William Baxley, who re-opened the investigation of the church bombing in [WORD ILLEGIBLE] said Sunday Rowe's testimony on the case was too unreliable to use. But he said Rowe is not a suspect in the bombing.

Birmingham Police Capt. Jack LeGrande, however, said Rowe is a "prime suspect" in the case.

On Sunday, in the article that began the latest wave of charges about Rowe, The New York Times reported that Rowe's lie-detector answers were "deceptive" - suggesting, at least inferentially, that Rowe himself might have been involved in placing the bomb.

Yesterday the Times and the Birmingham Post-Herald both reported a new Rowe story: that he had admitted killing a black man in Birmingham during a black protest demonstration in 1963. The Times report said that Rowe said his superior in the FBI instructed him not to tell anyone about the killing.

The story noted that investigators have not found records to substantiate a shooting such as the one Rowe has reportedly confessed to. The FBI, in its statement yesterday, also said there is no record that such an incident occured.

In a third Rowe story, the ABC-TV program "20/20" Monday night carried a report in which Rowe was accused of killing Liuzzo.

"20/20" carried interviews with two former Alabama klansmen who were convicted on federal charges in the Liuzzo case, largely on the basis of evidence provided by Rowe. They said Rowe fired the fatal bullet.

Rowe, who also appeared on "20/20," repeated his version: that he was riding in the car with the klansmen but did not fire a gun at Liuzzo.

ABC News then arranged lie detector tests for all three men, according to the "20/20" report. Rowe's answers indicated deception, the network said, while the accusations by the two klansmen "apparently help up."

Contributing to this report was Special Correspondent Andrew Kilpatrick.