Treating paedophiles in the community significantly reduces sexual re-offending, a study shows.

This is a key finding from a Corrections Department follow-up of community-based sex offender treatment programmes run by the Safe Programme in Auckland, Wellington Stop in the capital and the Stop Trust in Christchurch.

A study by Ian Lambie, of the Auckland University psychology department, followed up 175 adult male sex offenders who had received community treatment.

Offenders who completed the programmes had a recidivism rate of 5 per cent. In two control groups that did not receive treatment, rates were 21 per cent and 25 per cent, Wellington Stop manager Hamish Dixon said.

Dr Lambie, a specialist in forensic psychology, said the results for community-based programmes were as good as those obtained for prison-based treatment.

Though the four years of the study was a relatively short period to follow up offenders, other studies had shown that the greatest rates of re-offending occurred between two and four years after treatment.

The results showed the programmes were effective and had a positive effect on the community, Dr Lambie said. "When further sexual offending is reduced to this extent there are huge social and financial benefits to our communities, as there are fewer victims of sexual abuse in the future."

With specialist help, most adult sex offenders could be rehabilitated and integrated into the community.

The programmes are funded by several organisations, including the Corrections Department, Child, Youth and Family Services and community funding grants.

Mr Dixon said Wellington Stop, set up in 1993, was "very proud" of the success of its programmes. "We're up there with the best in the world."