LOS ANGELES, Feb. 14 – Shirley Nadell, a principle witness in the Tate-La Bianca murder case has fled California because of threats to her life, her attorney said Friday.

Mrs. Naddell, 31, received the threats while in a woman’s prison here from which she was paroled last week, according to attorney Wesley Russell.

One, he added, was contained in a note thrown into her cell and signed by Susan Atkins, 21, a co-defendant with hippie cult leader Charles Manson and four others in the murders.

Mrs. Nadell was the informer who told police late last year that her cellmate, Miss Atkins, had described how the murders were committed, had admitted her role in them and had implicated Manson and the other four.

Miss Atkins later related a similar story to the Los Angeles County Grand Jury and the indictment of all six persons accused of the slayings followed.

Mrs. Nadell was found innocent, but was held in the prison for several weeks for violation of probation.

Russell said Mrs. Naddell received a note from Miss Atkins, saying, “When I first heard you were the informer, I wanted to slit your throat.”

She also was the recipient of an anonymous note which said, “Death to squealer pigs,” he added.

Meanwhile, it was learned that Manson’s telephone privileges had been suspended by Los Angeles County jail authorities.

Welch said he suspended the phone privileges after conferring with Los Angeles County Superior Court Judges William B. Keene and George M. Dell when he discovered Manson had given a long interview to a San Francisco radio station. Judge Dell signed the order.

Manson, whose trial is set for March 30, is scheduled to appear in court Monday to argue a motion for a change of venue.