The Prime Minister says a letter sent from prison by the man accused of carrying out the March 15 Christchurch terrorist attack "should not have happened".
Yesterday it was revealed that accused gunman, Brenton Tarrant, managed to send a letter from Auckland Prison at Paremoremo. The letter was posted to the far-right message board 4chan.
Jacinda Ardern spoke to media from Tuvalu and said Corrections Minister Kelvin Davis is going to look into if current laws around prisoners' correspondence are "fit for purpose".
"I think I feel the same way about it as probably every New Zealander would feel," she said. "This particular communication just should not have happened.
"Obviously something has gone wrong in our system for this to have happened."
Tarrant, an Australian citizen, is being held in Auckland Prison at Paremoremo awaiting his next court appearance. He is accused of murdering 51 worshippers, attempting to murder 40 others and one charge under the Terrorism Suppression Act, following a shooting rampage at two mosques in Christchurch on March 15.
Under the Corrections Act 2004, sending mail is a legislatively required minimum entitlement for prisoners, however mail can be withheld in a very limited number of circumstances, and Corrections have withheld some of his mail where concerns have been identified.
The Department of Corrections chief executive Christine Stevenson has apologised to Christchurch mosque attack victims for the letter being sent.
"It is a fine balance to uphold our lawful obligations and mitigate all potential risks posed by the prisoner, however we are absolutely committed to ensuring that he has no opportunity to cause harm or distress, either directly or indirectly."