Two guards were attacked by a prisoner at a central Auckland prison this morning.
Police confirmed to 1 NEWS they received a report of the assault at Mt Eden Corrections Facility this afternoon.
A prisoner was placed in segregation today after an "unprovoked assault" on the two officers just before noon today, NZ Herald reports.
Mt Eden prison was then placed into lockdown for the rest of the day, with normal operation expected to resume tomorrow morning.
The prisoner could face criminal prosecution by police, or a change in security classification or internal misconduct charges.