An ex-prisoner, housed at a child sex offender unit at Rimutaka Prison, has claimed fellow residents are smoking synthetic cannabis while authorities turn a blind eye.
He said Corrections staff are, without knowing it, driving the men to places in the Wellington region where they buy the drugs.
The man, who RNZ has agreed not to name, is a convicted paedophile currently serving an extended supervision order, which expires in 2028. He must wear a electronic bracelet and is subject to strict conditions.
He's currently housed at Te Korowai, an 11-bed unit, outside the wire of Rimutaka Prison in Upper Hutt. It was opened in 2018 to house released prisoners who cannot find other accommodation - many of those who pass through the facility are child sex offenders.
It has strict conditions including 24-hour supervision, a curfew, and a zero tolerance policy to drugs and alcohol.
But the man said for the past month, three residents have been regularly smoking synthetic cannabis in the afternoon and evening.
"It's giving side effects of, obviously, fits, obnoxious behaviour, loud behaviour. Myself and other residents are stressed out from this and annoyed.
"These people, all they have to do is throw a little fit and they get whatever they want."
Synthetic cannabis is described by the Ministry of Health as a smokeable plant material containing synthetic cannabinoids that cause the user to get 'high'.
Many synthetic cannabinoids are more potent than cannabis and have the ability to cause significant physical and mental harm.
The man - who has been at the facility for less than a year - said he has complained to the police liaison officers four times, and community corrections staff six or seven times.
But he said still no action against them has been taken.
"No one's been charged, nothing's been stopped. Supposedly they were going to stop taking them in the vehicles to places they wanted to go, unless they stopped doing drugs.
"But none of that's happened - they're still getting driven around all the time."
He said the three men are able to go pick up the drugs at different locations in Lower and Upper Hutt. He said they get there by either walking, cycling, taking public transport, or even getting dropped off by Corrections staff.
In a statement, Corrections said it is aware of concerns regarding the use of synthetic cannabis by some residents at Te Korowai and the police are investigating.
But it said it houses offenders at the direction of the Courts and the Parole Board.
"We do not determine who is in prison and who is in the community," said District Manager, Gareth Fowler.
"Offenders in the community must comply with any conditions imposed on them by the courts or the New Zealand Parole Board.
"We take all instances of non-compliance extremely seriously, and hold offenders to account if they breach their conditions."
Corrections said they notified police of this behaviour back at the end of July and it is now an ongoing police investigation.
In a statement, the police say they are investigating reports of synthetic cannabis consumption.
"We are working in partnership with Corrections around the ongoing management and safety of all residents."
They say enquiries are ongoing and they can't provide any further comment.
"Synthetic cannabis is a dangerous substance and anyone affected by drug addiction is urged to seek help through the Alcohol and Drug Helpline on 0800 787 797, or free text 8681."