Letters that threatened a person, endangered prison security, or encouraged crime were just some of those confiscated by Otago Correctional Facility staff.
Information released under the Official Information Act shows staff at the prison withheld 12 outgoing letters, and three incoming letters, in the year ending June 30.
The reasons included threatening or intimidating the intended recipient, posing a threat to the security of the prison, encouraging an offence, and breaching a court order.
About 15,000 letters were sent from prisons nationwide each week.
Nationwide, 12 incoming and 299 outgoing letters were withheld.
In a statement, the Department of Corrections said letters could also be withheld at the request of one of the parties, if the receiver was under 16 and their parent or guardian requested it be stopped, or if it encouraged ‘‘hostility’’ to a person or group on one of the grounds specified in the Human Rights Act.
The news follows an apology from Department of Corrections staff after convicted Dunedin sex offender Eric Reihana Hepi was able to send his victim letters from prison.
Hepi was sentenced in the High Court at Dunedin last month to a minimum of 15 years, two months behind bars, after pleading guilty to a slew of sex and violence charges.
During his victim’s tearful victim impact statement, she revealed he was allowed to send her letters from prison despite the serious charges he was facing.
Corrections southern regional commissioner Ben Clark apologised to the victim and said an alert had been loaded in the system to stop a repeat incident.
Prisoner mail was also in the spotlight in August, when it was revealed the man accused of the Christchurch mosque shootings was allowed to send two letters from his prison cell that should have been blocked.
That incident sparked a review into the system, which in turn led to a raft of recommended changes.
Recommendations included setting up dedicated mail-monitoring teams, regular audits, and giving Corrections staff the power to read, copy, and store mail for intelligence gathering.
In October, the Corrections Amendment Bill, which strengthened the prisoner mail system, was passed.
