Controversy engulfed the House Assassinations Committee yesterday over the reliability of a former British police officer who says James Earl Ray told him in 1968 that he had killed the Rev. Martin Luther King Jr.

At the same hearing, a key alibi witness for Ray recanted earlier testimony.

At the end of its fifth open session on the King murder, the committee recessed until further notice.

The police officer in question, Alexander Anthony Eist, was assigned as a personal guard after Ray's arrest in London on June 8, 1968. Two weeks ago, he spokes to committee investigators about his conversations with Ray in jail there.

"There isn't any doubt from the conversation that he told me, that he has admitted to me, that he had done the murder," according to a transcript of Eist's statement to committee investigators. The statement was read into the hearing record yesterday.

"For what it is worth," Eist added, "I haven't any doubt in my mind that he did that on his own. For whatever reason he did it . . . he did it on his own. If it had been anything, or anybody behind him on that particular job . . . during the various and many conversation I had with him, it would have come out."

As soon as the 21-page statement had been read aloud, Ray's counsel Mark Lane protested, saying he had just received a telephone call from a British lawyer saying Eist had been "dismissed in disgrace" from Scotland Yard for corruption, perjury and robbery.

"If you knew of this man's background, you have done a disservice to the American people by raising the charges, Lane said. "This is perhaps the most outrageous thing this committee has ever done."

Reps. Richardson Preyer (D.N.C.) and Samuel L. Devine (R-Ohio), who had read the entire statement aloud at Ray's request, both told Lane the committee had not checked into Eist's background and did not necessarily accept the statement as true.

Lane said he did not know about Eist's background either - "all I know is what this British lawyer told me" - but the volatile lawyer was clearly upset at the panel airing charges by an unchecked witness.

Afterward, Lane said that he had been told Eist "was possibly the most corrupt man in the modern history of Scotland Yard" and that no one could have interviewed Eist without learning of his scandalous background.

Eist, now a pub owner in Six-Mile Bottom, Cambridge, told committee investigators he had come forward with his story because an American couple in his pub told him "this was probably something important to the country's sake."

Ray and Lane had been given copies of Eist's statement to read during the lunch recess.

"I think that is probably the most damaging statement against me," Ray told the committee, but he called it false. He said he has repeatedly told lawyers and the public that he would not make statements to other inmates and guards because "it is one of prosecutor's favorite tactics, when they have a weak case, to get these kinds of statements."

After the outburst surrounding Eist's statement, Ray was excused from further testimony but was told he will be called again, probably in November.

The witness who recanted was Coy Dean Cowden, a former mental patient and commodity broker who said last fall he had seen Ray at a service station in Memphis 6 1/2 blocks from the assassination scene shortly before King was killed.

Cowden, in statements to the National Enquirer and Lane, had identified Ray as being at the service station at the same time the King assassination was supposedly locked in a bathroom in a rooming house.

Yesterday, Cowden told the committee he wasn't even in Memphis on April 4, 1968, the day King was killed, but in Port Neches, Tex., more than 400 miles away.

Cowden said he had told the service station story as a favor to Renfro Hays, a Memphis private investigator who had spent a decade on the King case.

"Renfro Hays was a fellow who supported me for a period of about four months," Cowden said. "He befriended me, gave food and lodging."

Hays was trying to sell rights to information about the King murder, Cowden said, and asked him to help supply a story that would eliminate Ray as the assassin.

When the story was told to Lane, Cowden said, the lawyer "went for it, hook, line and sinker." Lane never questioned him to be sure the story was correct, but appeared really to believe the alibi, Cowden testified.

Lane writes extensively about Cowden's story in a book about the King murder, Code Name Zorro, co-authored with Dick Gregory.

The morning session yesterday was delayed 50 minutes to give Lane additional time to discuss the hearing with Ray. But even after questioning by the committee began, little new evidence surfaced because Ray refused to talk about his travels just before King was murdered until Ray and Lane had reviewed certain documents.

Ray was particularly interested in a 20,000-word statement he had given novelist William Bradford Huie shortly after his arrest.

On Thursday the committee had forced Ray into inconsistencies in explaining where he was during the week before King was shot. The committee wanted to establish that Ray had stalked King from city to city through the South, but Ray refused to answer more questions about his travels until he could "refresh his memory" by reading the statement to Huie.

The panel presented Amy Estelle Parsons, however, who was a counter clerk at the Piedmont Laundry in Atlanta during 1968.

Parsons, 71, testifying from a wheelchair, identified a laundry ticket she wrote out for Eric Galt, a Ray alias, on April 1, 1968. Ray has denied he was in Atlanta on that date, and told the committee Thursday that if he was in Atlanta then, "I'll just take responsibility for the King case right here on TV."

Parsons said the same Galt picked up his laundry on April 5, a day Rat admits he was in Atlanta.