LOS ANGELES, Aug. 11 – The police this afternoon released William E. Garretson after holding him for almost three days in their investigation of the slaying of Sharon Tate, the actress, and four other persons

The 19-year-old youth walked out of the police station with his attorney. He was a caretaker at the estate leased by Miss Tate and her husband, Roman Polanski, the movie director, where the bodies were found on Saturday morning.

The police said there was not sufficient evidence to hold the young man for further investigation. He underwent extended questioning yesterday while a polygraph machine recorded his reactions.

Meantime, police sources back away from earlier suggestions that there was a possible link between the Tate murder case and the slaying yesterday of a supermarket chain owner and his wife.

The bodies of Leon and Rosemary LaBianca were found at about 10:30 o’clock last night in their home in the Silverlake neighborhood of Los Angeles, about 12 miles from the Benedict Canyon estate were Miss Tate was killed.

Earlier conjecture had been that both crimes might have been committed by the same person because in both case the word “pig” was found smeared in blood.

“There is a similarity,” said Police Sgt. Bryce Houchin, “but whether it’s the same suspect or a copycat, we just don’t know.”

Four persons were killed with Miss Tate, who was 26. They were Jay Sebring, 35, a noted hairdresser; Abigail Folger, 26, a member of the Folger coffee family; Voyteck Frykowski, 36, a Polish screen producer and writer, and Steven Parent, 18, of El Monte, a friend of Mr. Garretson.

Mr. Garretson left the police station without answering reporters’ questions. His attorney, Barry Tarlow, said he had been prepared to go to court to require that the police either release his client or charge him. Mr. Tarlow also said Mr. Garretson was not able to give names of suspects.

Mr. Tarlow said that Mr. Parent was a friend of Mr. Garretson and had been visiting at the estate until about 11:30 P.M. Friday. Mr. Garretson, who lived in a building some distance away from the main house, did not know of the killings until the police seized him Saturday, the lawyer said.

Mr. Polanski, who returned home from London last night. A statement in his behalf was released through a public relations firm. It was attributed to Gene Gutowski, a friend and business associate of Mr. Polanski.

The statement denied that there had been any rift between the director and Miss Tate, who was eight months pregnant when she was slain. She came home by sea from London because of her pregnancy, Mr. Gutowski said. Miss Folger and Mr. Frykowski were staying in the Polanski home at the director’s request, the statement said.

Mr. Gutowski said a “cheap journalistic device” was responsible for a suggestion that the bizarre aspects of the slayings were somehow connected with Mr. Polanski’s movies. One of the films, “Rosemary’s Baby,” has been called a horrifying drama of witchcraft.

“Sharon and our other three friends were rational people with no interest in mysticism or anything else occult,” Mr. Gutowski’s statement said.

He also denied that there had been a party in progress before the murders, and insisted that “it is wrong to suggest that there was any romantic involvement between Sharon and Jay” Sebring, who was engaged to Miss Tate before her marriage to Mr. Polanski.

Mr. Polanski and Mr. Gutowski are owners of Cadre Films, which has produced “A Day at the Beach” and has in production “The Day of the Dolphin,” a spokesman for them said.

They were both prominent members of a group of Polish artists and writers who have emigrated to Western Europe and the United States as censorship at home made it difficult, if not impossible, for them to practice their professions.