Corrections Minister Mark Mitchell says he's not pushing for longer prison sentences, despite asking officials to look into how shorter sentences relate to higher levels of reoffending - and whether longer sentences allow better rehabilitation for offenders.
On Monday, the minister said people with longer sentences have more access to rehabilitation and therefore more successfully re-enter society.
The idea is only being looked into, but it's Mitchell's preference if it led to fewer victims overall - even if it required building more prisons due to an increase in the prison population.
But when asked by Morning Report on Tuesday whether this meant he wanted longer prison sentences for offenders he said: "No, that's not the case at all".
"The evidence shows that longer prison sentences gives you more time to be able to deliver programmes and to invest in people so that when they do come out they're better equiped to make good decisions..." Mitchell said.
Asked whether it was the rehabilitation programmes that were the key to the equation not the length of the sentence, the minister said: "So that's exactly why I've asked this piece of work to be done so that we can identify that, so that we can make the system better".
The idea has received criticism from the Opposition, and from academics.
Otago University criminology lecturer Fairleigh Gilmour told Morning Report people released on parole have lower reconviction rates, showing community rehabilitation programmes were also effective.
"We don't have to hold people in prisons, which is very expensive, to have those same impacts."
Rehab programmes within prisons helped, she said, but Corrections wasn't adequately resourced to offer them so a lot of prisoners missed out.
Increasing the prison population by extending sentences could make that worse, she said.
People given shorter sentences had less access to programmes and those with longer sentences were usually only able to access them in their last few years, she said.
"What we're actually just going to have is more people in for longer prior to being able to access those services."
Mitchell said with a law change prisoners on remand could now receive programmes, and people did not only have access to programmes near the end of their sentence.
It was clear being rehabilitated in the community did not work, he said, saying the previous government had a prison reduction target of 30 percent when there was also an increase in violent crime.
But Correction's Association president Floyd du Plessis told Nine to Noon the ministry was not funding support services to help prisoners with rehabilitation and help prevent them reoffending.
du Plessis said over the past couple of years there had been a stark rise in the prison population and everytime more beds were added "the department as a whole refuses to fund, resource and employ those support staff needed".
"Which means those prisoners are coming in, the resources are being stretched and no-one's getting meaningful engagement and rehabilitation."
It would only get worse without proper resourcing, he said.
Mitchell said the coalition has been clear it wants the seriousness of offending reflected in the consequences.
He hoped when offenders saw the consequences they would think twice about offending leading to a reduction in the prison population.
"I hope that that's the case, we'll just have to wait and see but the fact of the matter is, while we have people coming into the system, I want to make sure we're investing in them properly so they've got the best possible chance when they come out."
'Fix the courts'
Labour leader Chris Hipkins dismissed the suggestion longer prison sentences would help reduce reoffending.
Hipkins told Morning Report the opposite was generally true.
"Ultimately longer prison sentences generally tend to be associated with increased rates of reoffending rather than improved rehabilitation.
"The problem we've got with rehabilitation is the court system is so gummed up that it's taking so long for people to get through court that they're being released on sentencing because they've spent so much time on remand, and therefore they're not getting access to the rehabilitation programmes that they should be."
That was the problem, he said.
"Fix the courts. We've got to get the courts operating more efficiently. Justice delayed is justice denied. We've got to fix that problem.
"When people are staying on remand for years at time waiting to appear in court. When you've got victims showing up to multiple court hearings only to be sent home again because the hearing never happens.
"When you've got police spending a significant amount of time sitting outside court waiting for a case to be called and then going home at the end of the day not having had that case heard it shows that that part of the system is where things are falling down, the government are doing nothing to fix that."
Hipkins said it was a "massively inefficient" system which was costing New Zealanders money while being unfair to victims and leading to defendants being on remand and unable to access rehabilitation in prison when they should be.