Gary Thomas Rowe Jr., the FBI's top informer inside the Ku Klux Klan in the 1960s, charged yesterday that police officials in Birmingham, Ala., are secretly trying to discredit a network movie that implicates them in racial violence during the civil right movement.

In an hour-long interview with The Washington Post yesterday, Rowe also confirmed reports - leaked to the press by some Alabama police authorities - that he shot and killed a black man in Birmingham in 1963 while working as a paid FBI informer inside the Klan.

"It wasn't murder," he said. "I shot him in self defense . . . I swear to you I'm telling the truth."

Rowe said he reported the alleged killing to Birmingham police officials and the FBI. "But they told me to keep quiet about it and to forget about it. I couldn't believe it," he said. (Birmingham police spokesmen said they have been unable to locate information on any such killing but are continuing to investigate the matter.)

Now, Rowe says he has been "used and discarded by the FBI" and that police officials in Birmingham are out to get him by destroying his credibility.

In recent weeks, for example, Rowe has been accused of having been responsible for some of the bloodiest moments in the civil rights struggle. Birmingham Police Capt. Jack LeGrand has named the former Klan infiltrator as a "prime suspect" in the September 1963 bombing of the 16th Street Baptist Church in Birmingham, in which four girls were killed.

Two former Ku Klux Klan members, Eugene Thomas and Collie Leroy Wilkins, have publicly accused Rowe of firing the shot that killed Viola Liuzzo, a white civil rights worker, on a lonely Alabama highway on March 25, 1965. Thomas and Wilkins were convicted on conspiracy charges and served federal prison terms in connection with the case, largely because of testimony given by Rowe.

Rowe said yesterday that the charges by LeGrand, Thomas and Wilkins are part of an orchestrated attempt to discredit a movie entitled, "My Undercover Years With the Ku Klux Klan," based on his book by the same name. The film has been produced for NBC-TV by Columbia Pictures Television, based in Burbank, Calif.

"The main reason why all of this crap came up the way it did is because of this movie that's coming out," Rowe said. "LeGrand is the big instigator of all of this, and I can tell you why - this movie is going to embarrass the hell out of them [Birmingham police]."

Rowe said that LeGrand and other unidentified officials in the Birmingham Police Department are "trying to cover up" actions by department officials that directly contributed to, or condoned, racial violence in the 1960s.

Specifically, he charged that Birmingham police officers were directly involved in the 1961 beatings of "Freedom Riders" and that they may have known in advance that the 16th Street Baptist Church would be bombed.

"I absolutely believe that," he said of the bombing incident. "I absolutely believe that they [police] were involved."

Rowe also charged that the then mayor of Birmingham, Arthur Hanes, was a "card-carrying member of the Ku Klux Klan" during the early days of civil rights violence in Birmingham.

"That's fact," he said of his allegations against Hanes. "I personally turned in his Klan application to the FBI."

Hanes succeeded Matt H. Murphy Jr., who was killed in an automobile accident, as the defense attorney for the Klansmen who were charged in the Liuzzo case. Hanes could not be reached for comment yesterday. But his son, Arthur Hanes Jr., also a Birmingham lawyer, dismissed as an "outrageous lie" Rowe's charge that his father was a member of the Klan.

"That's really something," said the younger Hanes. "I can't believe that. It's the most outrageous lie I ever heard."

LeGrand, meanwhile, was on vacation yesterday and could not be reached for comment. But in a recent interview with The Post, he accused Rowe of being "an opportunist, a man who tries to play both ends against the middle."

He noted that Rowe has received a total of $50,000 for his book and movie rights, and scoffed at a suggestion that the Birmingham Police Department is taking an unusual new interest in a case - the church bombing - in which the department has made little progress in the last 15 years.

"We have been working all along to solve these murders," LeGrand said. "We have put a hell of a lot of our lives into this."

Still, the only conviction to come in the church bombing incident came last year largely as a result of the work of Alabama Attorney General William J. Baxley. And Baxley said he is convinced that the man convicted in the case, former Klansman Robert Chambliss, acted without any help from Rowe.

"I don't understand why all of this stuff is coming out now. All of his stuff is old." Baxley told Newsweek about the latest flurry of allegations against the ex-FBI informer.

Could Rowe be right?

"It might be possible" that someone is trying to undercut the NBC film, said Paul Klein, NBC's executive vice president for programming.

"I don't know what's happening, and I haven't had a chance to look at the film yet. But my understanding is that it is sort of an antiSouthern big city film," Klein said.

Rowe's book, ghost-written, depicts him as a dedicated American, risking his life to undermine an anti-American organization. NBC officials say the movie, starring sportscaster and former football player Don Meredith as Rowe, is not as flattering, but that it is sympathetic to his self-portrayal.

But what if LeGrand is right and Rowe is lying?

"We simply would have to remake the movie, change the whole focus, move a piece [of the original film] here and put another piece there. We'd find some way to salvage it . . . We're not going to eat all of the dollars that we're invested into this thing.We'll try to make something out of it," Klein said.

Published estimates are the NBC has already spent at least $1 million on the movie, which is completed and, according to NBC, is now being evaluated by lawyers. It can be aired anytime in the next two of three years, Klein said.