More and more high-risk criminals and sex offenders are being watched by Corrections even though their prison sentence is over.

Exclusive data released to Newstalk ZB shows the number of extended supervision orders has risen from 38 in 2005 to 215 a decade later - an almost 500 percent increase.

Victoria University criminologist John Pratt told Nadine Higgins the parole board is getting increasingly risk-adverse and is using exceptional measures "as a much more routine procedure for when these people finish their prison sentence."

Mr Pratt said it could also be due to public pressure but we have to remember in societies like New Zealand, human rights is not a one-way street.

"It runs both ways, both for members of the community and people who've done their time in prison and want to start afresh."

LISTEN ABOVE AS CRIMINOLOGIST JOHN PRATT SPEAKS TO NADINE HIGGINS