Yoko Ono said she opposed parole for the killer of John Lennon because he remained a potential threat 30 years after the ex-Beatle’s murder.

Mr Lennon’s widow said she was trying to be “practical” in asking that Mark Chapman remain behind bars for shooting dead the pop star on December 8 1980, outside Lennon’s Manhattan apartment building.

Mr Chapman, who has been repeatedly denied parole, is up for review again this month in New York State.

Ms Ono said Mr Chapman might be a danger to her, other family members and perhaps even himself. She did not elaborate.

At his last parole hearing, Mr Chapman said he was ashamed and sorry for gunning down the former Beatle. He told the parole board he understood the gravity of his actions and was a changed man.

Ms Ono, 77, made her remarks at a meeting of the Television Critics Association, while discussing a new PBS documentary on Lennon’s family and artistic life in New York in the 1970s.

LennonNYC, which will be shown on November 22 as part of the American Masters public TV series, includes rare studio recordings, concert film out-takes and home movies, producer Susan Lacy said.

Ono provided access and was among those interviewed for the documentary.

Reviewing her life with Lennon was “painful” at times, Ms Ono said, but provided the chance to show him as a “three-dimensional person” and to explore his ultimately tragic affection for New York.