JACKSON, Ga. (AP) _ A police informant testifying for convicted killer Wayne Williams said Tuesday that a Ku Klux Klan recruiter admitted taking part in the murders of several young blacks a decade ago.

Billy Joe Whitaker testified at the request of attorneys for Williams during a hearing in Butts County Superior Court.

Williams, who is serving two life sentences, was in court Tuesday, wearing handcuffs and a white prison uniform. It was his first public appearance since his 1982 trial.

Whitaker said Klan recruiter Charles Sanders had promised to kill a child who later was found murdered. Sanders also claimed the Klan was involved in a string of murders of blacks, Whitaker said.

Williams, 33, is appealing his two 1982 murder convictions in connection with the string of slayings of young Atlanta blacks between 1979 and 1981.

Whitaker said that at the request of police he wore recording equipment and visited Sanders several times at his home. He said he asked Sanders specifically about 14-year-old Lubie Geter, one of the victims, whom he had heard Sanders threaten months before.

''I said, 'You killed that damn Geter kid,' and he said 'Yeah, we damn sure did, we killed a lot of them niggers,''' Whitaker testified.

Whitaker said he had been with Sanders earlier when the child ran into Sanders' van with a go-cart.

He quoted Sanders as saying ''I'm gonna choke him to death ... and put him on Martin Luther King's grave.''

Whitaker said he contacted a Georgia Bureau of Investigation detective from jail in 1981 after he heard that Geter had become one of the black children slain. He was then recruited as an informant.

In his testimony, Whitaker was unclear about why he was in jail. His record includes car theft, burglary and shoplifting.

Police say they do not know where Sanders is.

Whitaker testified that he had worked as an informant for detective Aubrey Melton, who has since died. He said Melton asked him to keep seven of the tapes police had made during Whitaker's undercover work. ''He said, 'This is something we're covering up,' '' Whitaker testified.

Williams' attorneys are seeking to prove that their client, who is black, was framed for a series of killings that actually involved the Klan.

George Napper, Atlanta's police chief at the time of the slayings, was questioned extensively about the investigation into Klan involvement in the slayings. He insisted he could not recall ever hearing of Whitaker or any confidential informant who was providing such information.

Napper said he had heard the Klan involvement theory and believed he had read it in newspaper accounts of Williams' trial.

But Maj. Herman Griner, who was head of intelligence and reported directly to Napper at the time of the 1981 investigation, testified that he briefed Napper from ''time to time'' on the Sanders investigation.

Whitaker testified that Sanders once took him to a home where Klansmen were keeping bazookas, explosives and police uniforms. Williams' attorneys contend white supremacists sometimes posing as police officers were killing children in Atlanta in an attempt to start a racial war.

Although most of the victims were black children, Williams was convicted of killing two adults, Jimmy Ray Payne, 21, and Nathaniel Cater, 27.

Prosecutors presented evidence at trial linking Williams to 12 of the 29 killings between 1979 and 1981. In all, police blamed him for 22 slayings of young blacks.