Two prison officers were assaulted in separate incidents at Auckland Prison at Paremoremo in October.
The Department of Corrections says both attacks at the high-security prison were carried out by the same inmate.
It is not divulging the identity of the accused offender but say he has been moved to a different part of the prison in order to segregate him from other prisoners.
The matter has now been referred to the police and no further comments are being made.
Neither prison officer was seriously hurt but both needed to have their injuries assessed in hospital.
The department says it takes the issue of violence in prisons extremely seriously and its top priority is staff safety.
It says it is working continuously to improve safety and security at all prison sites.