A prisoner has died and another has been injured in separate events at Auckland Prison over the weekend.
A man was found dead in his cell on Saturday, and the Ministry of Corrections is investigating, though they say his death is not suspicious and has been referred to the Coroner.
Auckland Prison general manager Steve Parr said the man was not double bunked in his cell.
Staff also intervened in a fight between three prisoners on Sunday, in which one prisoner sustained what Corrections calls a puncture wound.
No staff were injured.
He was taken to hospital but was expected to return to prison on Monday.
"The perpetrators were relocated to the management unit and have been placed on directed segregation," Parr said.
"Prisons can be volatile environments, and we are constantly working to ensure our prisons provide the safest environment possible for staff and prisoners.
"Auckland Prison accommodates the country's most dangerous and volatile people. Many prisoners have long histories of antisocial behaviour, and can behave unpredictably and act without warning."
More than 80 percent of the prison population had convictions for violence in their offending histories, Parr said.
"We have a zero tolerance for violence policy, and any violence or assaults against other prisoners or staff is not tolerated in prisons."
Parr said any prisoner using violent behaviour would be held to account, including facing criminal charges.
Police are investigating the fight.
