Police have charged a man over an alleged assault that hospitalised an inmate at Paremoremo prison.
A 35-year-old has been charged with wounding with intent to cause grievous bodily harm and is scheduled to appear in the North Shore District Court in June.
Prison Director Andy Langley said a prisoner was taken to hospital on May 7.
Langley said staff had responded immediately and sought medical assistance for both the victim and perpetrator.
"The area in which the assault took place was secured as a crime scene and all evidence has been provided to police, including CCTV and On-Body camera footage.