A program centering on group work therapy has curtailed the recidivism rate among sex offenders as measured against those who served time but didn't participate, the Justice Ministry said.

"A certain degree of effect has been observed," the ministry said Friday in releasing its first report on the program's impact.

Offenders incarcerated for sex crimes such as rape and indecent assault and who were judged likely to repeat were picked to take part in the program. Introduced in 2006 at selected prisons and probation centers nationwide, it took cues from similar initiatives introduced in Canada and the United Kingdom, according to the ministry.