A justice advocate says an investigation into whether Police are racially biased against Māori isn't needed because we already know the answer.
Police announced the long-term research project on Tuesday and said it will be done in partnership with Te Puna Haumaru NZ Institute for Security and Crime Science at the University of Waikato.
But justice advocate Emilie Rākete says there doesn't need to be another review and bias against Māori is well-documented.
"It's not a mystery and it's not a secret. The police know it and we know it so the report is repeating work that's already been done," Rākete says.
Police Commissioner Andrew Coster insists this review has been in the pipeline for some time. He says it isn't in response to recent allegations of racism over police using tactical force against Māori offenders more than any other ethnic group or the photographing of young Māori.
"The question is are there ways we are operating today that are causing unfairness for a particular group," Coster says.
Coster does admit Māori are over-represented in criminal justice outcomes, but won't say if the police are biased.
"Police are at the bottom of the cliff for a range of problems like family harm, like mental health, like drugs and alcohol."
The Police Commissioner says there are three key areas the research will focus on:
who police stop and speak to
their use of force
their decision-making around prosecutions.
Sir Kim Workman is chairing the external reference group and he insists this research is different.
"Quite a lot of work has been done that identifies bias, this research is about doing something about it."
There's no timeline yet for when the research will be finished.