Tackling colonisation, institutional racism and employing tikanga-based justice methods are key to reducing the Māori prison population, researchers say.
A report, They're Our Whānau, documents perspectives of more than 900 Māori people on New Zealand's justice system.
Māori make up just over half of the country's prison population, while making up just 15 per cent of the general population.
The report argued to put Māori perspectives at the centre of justice policy.
"No policy should be decided by elected representatives without the full and direct participation of members of the group[s] affected by that policy," the report said.
ActionStation collaborated with a group of fourth-year medical students at the University of Otago, under the supervision of Dr Keri Lawson-Te Aho, to conduct the research, which included a 28-question online survey, interviews with experts and perspectives from the Safe and Effective Justice Summit in August.
A vast majority (90 per cent) of survey respondents said structural racism, intergenerational trauma, and colonisation were the reasons more Māori were in prison than non-Māori.
The report argued the displacement of Māori from their land, identity, language and justice system created a cycle of "intergenerational trauma", still affecting Māori today.
In having fewer resources and less wealth than Pākehā, more Māori were pushed toward acts of survival that were subsequently punished by the justice system.
There were also no prisons before colonisation. The system for justice in Aotearoa was based on tikanga, which describes the ways of doing and thinking held to be just or correct (tika) in the Māori worldview. This system restored mana and balance when harm against whakapapa had occurred.
This differed to the Pākehā approach, which took an individualistic approach to accountability, rather than the collective accountability favoured within the Māori worldview.
ActionStation director Laura O'Connell Rapira said in making the report public they wanted to broaden the conversation about justice solutions.
"We want people to think more about historical events like colonisation, and to ensure the Government's inquiry, Hāpaitia te Oranga Tangata, engages with Māori and puts these perspectives at the centre."
Solutions also needed to involve wider societal changes, with the vast majority of survey respondents listing poverty and survival as the main drivers of crime.
In prisons 77 per cent of people had once been a victim of violence, 64 per cent suffered a traumatic brain injury, two-thirds do not have basic literacy skills, and more than 90 per cent have mental health or addiction issues.
There were also 23,000 children who had a parent in prison, children who were nine times more likely to end up in prison than children without a parent in prison.
"We are locking up people who have been failed by our social services," Rapira said.
"If we want to ensure we are not spending a huge amount of money incarcerating people we need to look at what we can do outside the prison system."
Key changes needed to happen in prevention, reducing poverty and devolving power to hapū and iwi to design Maori-led approaches.
Rangatahi Courts, like Youth Courts but held on marae and which follow Māori cultural processes, had proven to be effective examples, Rapira said.
But kaupapa-based prisons were not what they were talking about.
"Prisons didn't exist before colonisation, so putting up a prison with some Māori designs is not really a solution," Rapira said.
"Tikanga, language, cultural programmes in prisons are really powerful, but is prison the right place for that? In an ideal world that would be happening outside of prison."
In preventing and reducing crime 80 per cent of survey participants supported connected communities, 76 per cent mental health services, 73 per cent addiction support services and 71 per cent jobs and higher wages.
The majority of participants (76 per cent) also said community-based interventions should be supported and funded instead of prisons.
Sixty-five per cent disagreed with the Government's planned expansion of Waikeria Prison.
Respondents also felt Māori were unfairly represented in media, and that crime rates were increasing, when they were actually decreasing.