The chair of the Parole Board says new figures showing the number of serious criminals reoffending has dropped dramatically are gratifying, but no cause for complacency.
Sir David Carruthers says research into the decisions of the board shows the number of offenders committing crimes while on parole has more than halved in the past 10 years.
Speaking at the Australasian Parole Conference in Rotorua on Wednesday, Judge Carruthers said even the board was surprised by the drop in the rate of offending while on parole - as the number of parolees has doubled to 1600 over the past decade.
In 2002, the number of long-term offenders who reoffend while being managed in the community before the end of their sentence was about 100 a month.
Parole Board figures show that number is now 45 per month.
Sir David says this proves with correct risk assessments, parole works and it is in everyone's interests to create a regime to help offenders stay out of trouble.
The Parole Board says the figures are hugely gratifying and prove that its approach works with the right risk assessments.
Last year the board held 4546 parole hearings and declined 70.6% of them.
The percentage of inmates who have completed more than two-thirds of their sentence has risen from 10% in 2004 to nearly 50% today.