Former attorney general Ramsey Clark said yesterday the Justice Department did not take control of the investigation of Martin Luther King's assassination because it would have worsened relations between him and late FBI director J. Edgar Hoover.

He said that although there was a "quality of racism" in Hoover's attitude toward the civil rights leader, the FBI investigation of the killing was thorough.

"The FBI's reputation was on the line," Clark said. "Failure to perform self informed, he gave the FBI a free hand in setting the direction of the investigation.

He testified before the House Assassinations Committee, which has criticized both the FBI and Justice Department, saying they failed to investigate adequately the possibility of a conspiracy in the April 4, 1968, assasination of the civil rights leader.

Committee investigators say they have turned up indications that the brothers of James Earl Ray may have played a part in the assassination.

Ray is currently serving a 99-year prison term for the assassination. He has recanted the confession he made before pleading guilty to the assassination in 1969.

Clark said although the FBI investigated various conspiracy theories while he was in the Justice Department, "I don't recall any representation of evidence that ever implied the direct involvement of another person."

To have asserted his constitutional authority as attorney general ad taken control, Clark said, "probably would have been worse in terms of already strained relations" with Hoover and the FBI.

The committee has said the Justice Department failed to use investigative techniques such as convening a grand jury or creating a strike force to make sure any conspiracy in the King killing was uncovered.

Clark said those techniques were not used in the King assassination investigation because neither would have worked.

He said that after Ray was captured in London in June 1968, he wrote a memo to Hoover, urging an investigation of the possibility that other persons were involved in King's killing.