Key Points:

One Rimutaka Prison inmate stabbed another during a dispute over a feral cat they had befriended, the Corrections Department has confirmed.

A convicted rapist and murderer nearing the end of his prison sentence stabbed his room-mate six times in the neck for scaring the cat, the Dominion Post reported.

The Boxing Day attack was sparked after the prisoner entered the living room he shared with another man in the prison's minimum-security unit, startling the cat and causing it to scamper away.

The two men were prisoners in the self-care unit used to prepare long-term inmates for release.

The man would have been killed if a third inmate had not stepped in, Corrections Association president Beven Hanlon said.

"That prisoner is lucky to be alive."

Corrections acting southern assistant regional manager Tony Howe confirmed there had been an attack with a "makeshift weapon" during a dispute over a feral cat.

The injured man was taken to Hutt Hospital under escort but returned to the prison on December 28.

His attacker is now in a high-security area.

Both police and the Corrections Department are investigating.