The 16 men rioting at Waikeria Prison gave themselves up peacefully at 12.37pm today, Corrections Minister Kelvin Davis says.

They received food and water and will soon be transported to other prisons around the country.

One prisoner - who was attacked by the rioters - was hurt, Davis has just told the media at a press conference in Wellington.

The top jail has been completely destroyed and can no longer be used, Davis says.

Police are the only agency who can lay charges on the men for their actions.

Davis says the prisoners never raised any problems about their living conditions before protesting. He does not believe the men were protesting for the reasons they say they were.

He says he has acted behind the scenes, receiving updates hourly most days. He thought the containment should be left with Corrections staff who are trained for situations like this.

Corrections Minister Kelvin Davis. (Photo / NZME)

Davis thought the men wanted political attention and he did not speak out in fear of encouraging other prisoners from taking similar action.

Asked about his apparent lack of communication amid the rioting, Davis says his role was to leave the response to the experts.

The prison population at Waikeria has decreased by 20 per cent since March 2018, Davis says.

Department of Corrections incident controller Jeanette Burns says there are extensive processes and actions in place when riots like this take place.

She says Corrections were "always in control" of the situation.

Last night, staff made an attempt to bring the stand-off to a safe end but were met with hard resistance from the rioters, Burns says.

Staff retreated after more fires were lit and debris was thrown at them.

This morning, the 16 men indicated they wanted to give up and by just after midday they were all off the roof.

Burns acknowledged the front-line staff who responded to the event, saying they were "outstanding".

Department of Corrections chief executive Jeremey Lightfoot reiterated Burns's comments, saying all agencies worked together well to enable it to finish safely.

A number of reviews are underway: Two internal commissioned by Lightfoot.

One will be an operational review, from which they will learn, he says.

The operational review should be finished within three months.

A second wider review has also been commissioned and will enable Corrections to consider some of the wider issues of the event and may take between six and nine months to finish.

The actions of the rioters exposed them, other prisoners, Corrections staff, and emergency services to harm, Lightfoot says.

"There is no excuse for the things these men have done," he said.

Water comes from a bore and treatment plant, tested six days a week, and there have been no concerns with the water, Lightfoot says. Staff use the same water.

A number of steps have been taken to improve conditions in the top jail, including the repainting of some cells.

Yards are checked daily and fixed when needed, Lightfoot says. There are increased resources in the property area so prisoners can receive them quickly.

There are a number of channels for prisoners to make complaints or raise concerns, Lightfoot says.

They include the Ombudsman, a form to fill out, and a free 0800 number for prisoners to call.

Corrections expects a new facility they are building at Waikeria to replace the top jail to be finished by 2022.

About $10,000 is spent per month on replacement clothing at Waikeria.

The 16 inmates who overran the prison last week finally surrendered about noon today, Māori Party co-leader Rawiri Waititi announced in a statement about 1pm.

Waititi arrived at the prison this morning after travelling through the night to meet the 16 inmates after they asked to speak with him, he said.

"They were ready to come down," Waititi said. "Naturally, they were tired and hungry but still very determined to see change.

The group had been evading capture on the jail's roof after starting a riot and lighting damaging fires in the prison yard on Tuesday afternoon.

They had been making threats at staff and police, throwing debris at them from the roof of the buildings.

The majority of those involved in the event were members of the Mongols and Comancheros gangs, Corrections Minister Kelvin Davis said today.

Five of the men were deportees from Australia, with three subject to returning offender orders because of their criminal convictions.

It's the first time Davis has commented on the six-day uprising.

"I made the decision not to bow to the demands of these men nor make public comment that would have simply opened up political negotiation with them and achieved nothing to bring the event to a safe resolution."

The group had destroyed the 'top jail' facility at Waikeria Prison, rendering it unusable, he said

Responsibility for laying charges in relation to the destruction of the facility is with the police, Davis' statement said.

"The arson, violence and destruction carried out by these men were reckless criminal acts that put themselves, other prisoners, Corrections staff and emergency services in danger," Davis said.

The inmates were protesting about a number of things, from their water reportedly being brown, bedding being unclean, and being fed food from paper bags.

Waititi, the MP for Waiariki, says people must serve the time for their crimes but they deserve to be treated in a humane way.

"Even prison guards acknowledged to us that the state of the unit was unacceptable," he said.

Māori Party co-leader Rawiri Waititi, the MP for Waiariki. Photo / Andrew Warner

"They have achieved what they set out to do when they embarked on bringing attention to their maltreatment in prison.

"When injustice is normalised, defiance and protest is necessary. These men are the product of such injustices and through their protest they have changed the face Corrections forever.

"These men are not animals, they are humans; they are brothers, fathers and sons and are deserving of better treatment.

"If you treat a person like a dog, they will act like one and that is the saddest part of this whole saga; a failed criminal justice system adopted from a land 19,000 kilometres away."

Waititi addressed an audience on the Māori Party Facebook page, along with orator and Waikato reo and tikanga expert Rahui Papa.

"We've been involved in the kaupapa today to support the safe surrender of our whanau," Waititi said.

He said inmates were treated with respect upon surrendering.

Waititi said mana whenua and local iwi helped with negotiations.

"We've cleared the pathway for I think a successful operation."

"We're really really pleased with the way things have happened."

Waititi said mana whenua protocols were adhered to during negotiations.

"But the big move is heading forward."

Waititi also cited the Ombudsman's report, released last year, which cited hygiene and maintenance issues in parts of Waikeria.

"This was indicative of a failing system for our people."

He said it was also important Corrections workers were safe.

"We can move forward together for a brighter future."

Much of the prison is now inhabitable, after the rioters destroyed more than a third of Waikeria's bedding capacity by midweek.