Labour and the Green Party have called for the government to cut all ties with private prison company Serco, following the release of a report into fight clubs at Mt Eden prison.
The long-anticipated report which Serco had tried to block was released yesterday, revealing the extent of the nearly-weekly fights that were largely organised by gangs.
Serco began running Mt Eden Prison in 2011 but was stripped of the contract in mid-2015 after reports of assaults and organised fight clubs.
Serco continues to run Wiri Prison.
Labour's corrections spokesperson Kelvin Davis said the government should be ashamed of what was happening in the country's largest remand prison.
"I mean there's multi-layers of failure here. There were the prison guards who didn't pick up on what was going on, their bosses didn't pick up what's going on, prison monitors didn't pick up what's going on, the prison inspectorate didn't, [and] the ombudsman who has a role in monitoring prisons didn't pick it up," he said.
The government must give Serco the boot from Wiri and commit to not reprivatising Mt Eden, Mr Davis said.
Green Party co-leader Metiria Turei said Serco was clearly not fit to take care of public money or prisoners.
"Clearly Serco have put profits above their responsibility to the New Zealand people. All contracts with Serco should cease immediately and the government should confirm that Serco will not receive any government contracts in the future," she said.
Both the Green and Labour Parties said what happened was the result of privatising the prisons.
Fight clubs happened before prison was privatised - Corrections Minister
However, the Corrections Minister Judith Collins said fight clubs were recorded at the Mt Eden remand facility in a 2009 report, before the prison was privatised.
"There has been a history of it from time to time particularly around particular prisoners.
"You're talking about very violent criminal gang leaders and unless they are dealt with in a very stern way, they will continue to do this," she said.
However, Ms Collins said it was clear the Corrections Department did not meet its monitoring obligations.
All 21 recommendations from the report will be taken up, she said.