A review is underway into how to keep the skyrocketing prison population under control.
Photo: RNZ / Cole Eastham-Farrelly
Labour plans to reduce prison numbers by 30 percent over the next 15 years.
The Corrections Minister, Kelvin Davis, said a team was investigating how the justice system could best intervene with young offenders.
He said they were also looking into the effects of social development, health and education.
Mr Davis said the current system wasn't working.
"At the moment the prison muster is well over 10,000, creeping up to 11,000. Just the forecasts for the prison population from a year or so back said that by 2024 we'd get up to 10,088, that's eight years away and we've already surpassed that figure."
