Prisons run by private companies are not an option, Corrections Minister Paul Swain says.
Opposition parties have said that ending private participation in the prison system is a triumph of ideology over commonsense, but Mr Swain said the simple issue was that private companies should not make profits out of prisoners.
However, Auckland Central Remand Prison (ACRP) was well managed before it was handed back to the state today.
"In the end, we have a public prison service, a public police force, a public courts system," he said on National Radio.
"This is a role the Government or the public should be involved in, not the private sector."
National's law and order spokesman, Tony Ryall, agreed ACRP was a success while it was run by the GEO Group.
"It's performed about the same as those in the public sector," he said.
National and ACT support privately-run prisons and have said there will be more of them if there is a change of government.
National's law and order spokesman, Tony Ryall, said today private management did a better job.
"On value for money, for what you get, Auckland Remand Prison was providing more education and literacy, improved health services, and a much better deal for the taxpayer," he said.
Mr Ryall said ACRP had been running at a cost of $43,000 per inmate per year, against $54,000 in public sector prisons.
The managing director of the GEO Group, Peter Bezuidenhout, said his company had delivered far more than was required under the contract to run the prison.
"We've done exceptionally well...we offered a cost-effective solution. We've met all our contractual obligations, but still we have to give it back," he said.
Mr Bezuidenhout said his company would be "knocking on the door" if there was an opportunity in the future to run prisons in New Zealand.
"One of the great benefits of having independent commercial operators, outside the public system, is that they set a benchmark for performance," he said.
"We don't want to be dragged into political debate ... it was an election promise and Labour had to live up to that.
"There was no desire from the Department of Corrections to get rid of us."