A convicted killer has today admitted stabbing a fellow prisoner with a home-made shank in a "frenzied attack".
Terry Jason Nahi is serving a life sentence for the murder of 21-year-old Christchurch woman Lisa Caroline Hurrell in 1998.
Today at Christchurch District Court, Nahi pleaded guilty to a brutal prison assault at Christchurch Men's Prison on May 4 this year.
Nahi, 42, armed himself with a shank and walked into an inmate's cell in the Rawhiti 2 wing about 8.15am, the Crown summary of facts says.
"What the f*** are you doing Terry?" the victim was heard to say.