WASHINGTON (AP) _ Former Mayor Marion Barry says the fellow inmate that accused him of publicly engaging in sexual activity in a prison visitor's room was ''just trying to bash'' him and get his own sentence reduced.

In an interview Sunday with a local television station, the former Washington, D.C., mayor forcefully denied that a woman performed oral sex on him in a crowded prison visiting room.

''He's just trying to bash Marion Barry and get his sentenced reduced,'' Barry said, calling media coverage of the allegations ''vindictive and irresponsible'' journalism.

Federal officials are investigating a claim by inmate Floyd Archer Robertson that a guard helped arrange the visit between Barry and the woman, who has not been identified.

''We're going to go ahead and take a look at it,'' Gregory Bogdan, spokesman for the U.S. Bureau of Prisons, said Sunday. Barry, a three-term Washington mayor, began serving his sentence last Oct. 26 after exhausting appeals.

Robertson, jailed for distribution of a controlled substance, said the woman performed oral sex on Barry in front of at least 30 people in the visiting room.

''Art Robertson is a convicted felon. He has at least 5 or 10 years of time to do in the federal prison,'' Barry said. ''He masqueraded as a physician, and they are taking this as gospel. They won't check out his word, his motivation.''

Robertson said Barry confronted him after Robertson complained to prison authorities.

''He said that if I complained, there would be repercussions,'' Robertson said. ''It sounded like a threat to me.''

Two days after Robertson made the complaint at the minimum-security Petersburg prison, he was moved to a prison in Butner, N.C.

Barry said Robertson was transferred becausee other inmates were ''resentful of his lie.''

''My character is strong enough I wouldn't do it,'' Barry said. ''My principals are strong enough I wouldn't do it. I couldn't do it.''

Robertson told prison officials the guard, with Barry's knowledge, helped have the woman admitted.

''It was quite implied that it was a hooker,'' Robertson told The Washington Times. ''I can say with all certainty it was not someone who had been put on the visitors' list by (Barry).''

Federal officials declined to identify the guard, and spokesman Bogdan would not say whether he had been reassigned or put on administrative leave.

He said if the allegations are found to be true, Barry could face disciplinary action ranging from curtailment of visitation rights to transfer to a more secure prison.

Sexual misconduct in prison visiting rooms ''does occur, but it happens infrequently,'' Bogdan said.