Ground-breaking work on fairness and equity within New Zealand's police force has quantified for the first time the gap between Māori and Pakeha when it comes to how they're treated.

It comes from the world-leading project Understanding Policing Delivery, which granted a research team unrestricted access to police staff and data.

Controlling for all other relevant factors, including previous criminal history, youth and gang affiliation, Māori are still 11 percent more likely to be charged with an offence than a Pakeha person in the same situation.