Police are considering extra security for some Paremoremo prison officers after releasing their personal details, including where they live, to gang members.
The information, which was supposed to be censored, was disclosed in court documents for an upcoming case after inmates at the prison assaulted guards.
The Corrections Association said two of the officers were stabbed and needed hospital treatment.
Waitemata district commander Superintendant Tusha Penny said police found out about the mistake, which was the result of human error, last week.
Ms Penny said the police have expressed their deep regret to the Department of Corrections, and they were working closely together.
They were discussing appropriate security measures for the affected staff members and their families, she said.