Corrections boss Christine Stevenson says it will take a multi-generational shift to reduce the number of Maori behind bars

A new strategy unveiled today aims to lower Maori prisoner numbers by a third over 15 years.

Stevenson says there hasn't been a Maori-focused strategy for at least a decade.

She says the strategy focuses on the individual in the context of their family and community rather than on the crime.

Stevenson says the point of prison is to not punish further but to help people so they don't come back.