The Sensible Sentencing Trust says Māori are to blame for the high rate of prisoner reoffending, not Corrections or the justice system.
It follows a Waitangi Tribunal report that moved some of the blame for Māori re-offending to the Corrections Department.
Forty-one percent of Māori prisoners are back behind bars within two years of freedom. It's a sign the Department of Corrections has failed, and that was spelled out in a Waitangi Tribunal report, which says Corrections doesn't have a plan.
"I think everybody has admitted that is the case - even the Corrections staff and the politicians," former Māori Affairs Minister Sir Pita Sharples says.
But the Sensible Sentencing Trust disagrees. Garth McVicar says this is a Māori problem and Corrections shoulders no blame at all.
"We've got a problem, but it's not a correctional problem. It's not the Corrections Department's problem. It's Māoridom failing their kids. Simple as that," he says.
But Sir Pita says it's not simple at all.
"[Mr McVicar] really needs to look at the world and see how things really work. He needs to look at New Zealand's culture and how we can work together," he says.
"This is a problem for all New Zealanders."
Sir Pita says the Waitangi Tribunal report makes it clear the system is failing and Māori and Corrections have to work side by side.
He's leading a push by iwi leaders for specialist Māori rehabilitation. They want new Kaupapa Māori prisons and to work more closely with offenders' families to create change inside and outside the walls.
"It's a no-brainer really, to do something about it. New Zealand's just been giving lip service to this and they haven't put anything real in there that will change the situation," Sir Pita says.
Mr McVicar says the problem is Māori parents, not prison, and denies he's racist for saying so.
"We shouldn't be labelling people racist because they challenge someone else's thinking."
One thing all parties agree on is that Māori have a vital role to play in keeping their community outside prison walls.
But Sir Pita says first, Corrections has to let them, and he'll meet with the department in the next few weeks to push for Māori to be more involved.