A quarter of child sex offenders under special supervision after their release from prison have breached their conditions, figures show.
Also, one in five has been convicted of a new offence.
Corrections Department figures issued under the Official Information Act to the Sunday Star-Times newspaper show that each year since extended supervision orders were introduced in 2004, dozens of offenders have broken the rules.
In 2008-09, when there were 142 orders in place, 55 people breached conditions and 41 committed offences.
The orders, which allow the worst child sex offenders to be monitored, applied to 227 people as of July this year.
In Whanganui, the local community is protesting the release of serial sex offender Stewart Murray Wilson into a house on prison grounds despite stringent monitoring conditions in place until 2015.
Corrections refused on privacy grounds to supply the details of all offenders under special supervision but in a recent case, convicted paedophile Te Rito Henry Miki escaped his conditions by using a fake CV and birth certificate to get jobs in six North Island schools before being caught out this year.
Breaches of conditions can include minor acts such as using a cellphone, accessing the internet or drinking alcohol when prohibited.
Corrections Services manager Maria McDonald said the high breach rate reflected the fact that they were high-risk offenders but also reflected the low tolerance to breaches.
Where breaches or new crimes are suspected, monitored offenders can be arrested without a warrant and held in custody until a court appearance.
The government is drafting legislation for public protection orders, which would go a step further and allow courts to keep some high-risk offenders in jail beyond their original sentence.