The Corrections Department says an attack on staff at the Northland prison was not linked to double bunking.
Labour MP Clayton Cosgrove on Tuesday asked the Corrections Minister in Parliament how she could reconcile her stated desire to improve prison safety with her intention to press ahead with double bunking in jails.
He said an attack on prison officers by 15 inmates on Monday resulted in serious injuries.
But the Corrections Department says the unit is running exactly as it should be.