The Ombudsman has unearthed evidence of some prisoners being filmed while strip-searched or using the toilet.
The findings were made by inspectors on unannounced visits to four jails, operating under the Crimes of Torture Act.
At Arohata Prison in Wellington, the inspectors found prison staff observing prisoners through camera footage using the toilet, in various stages of undress, or being strip-searched, which amounted to degrading treatment or punishment.
A prisoner at the Otago Corrections Facility had waist restraints and handcuffs for about 10 weeks.
This was to combat self-harming, but was considered disproportionate and unreasonable by the inspectors.
The prisoner was un-cuffed every two hours during the day and for four hours at night to stretch his muscles, take a shower or eat meals.