Corrections has apologised for not telling eight schools and four childcare centres in south Auckland that sex offenders were being housed nearby.
The ministry says it's now reviewing its processes and checking to ensure the same mistake hasn't happened anywhere else in the country.
It's been revealed 11 sex offenders live at two boarding houses on the same street in south Auckland. Newshub can't identify the street, but can say that eight schools and four childcare centres are nearby.
Despite eight of the sex offenders living on the street for more than two years - not one of the schools or childcare centres was informed.
Principal of Otahuhu Primary School, Jason Swann, told Newshub the fact he wasn't told is a major concern.
He says Corrections should've warned him so he had all the information to ensure his young students are safe.
"I would've thought that was correct procedure anyway - that's what we've been lead to believe in the past," Mr Swann said.
Corrections today apologised, saying it got it wrong.
"We're very sorry for that - we should have spoken to those principals earlier," Corrections Department spokeswoman Jeanette Burns said.
Today Corrections staff met with all eight schools and most of the daycare centres to inform them about the sex offenders and outline what protections are in place.
The department says they weren't informed earlier because the area where the boarding houses are was deemed an industrial zone, despite being less than one kilometre from several schools.
Newshub asked Corrections whether it could guarantee this hasn't happened anywhere else in New Zealand.
"We're going back now and we're looking at where all of these properites are where these offenders are in, and we're looking at whether those notifications were done," Ms Burns says.
There is a full time supervisor at the Otahuhu boarding houses and extra support has been brought in. Most of the sex offenders are fitted with GPS devices. They can still walk past a school but if they linger police are alerted.
"We are monitoring these offenders very closely," Ms Burns said.
Several principals Newshub spoke to said they don't have enough information to immediately decide whether the sex offenders should be moved on.
They understand the offenders have to live somewhere but the principals say they need to be informed to make sure they're giving parents and students the right safety messages.
Sex offenders can't live within 500 metres of a school or daycare. At least one of the schools near the Otahuhu boarding houses is just outside that boundary.
Corrections says due to the housing shortage there's no where else the sex offenders can go. It says it can take a hundred phone calls to place just one offender.
Newshub tried to speak to some of the people that live at the boarding house, as well as the owners, but no one would comment.
Neighbours say they don't want the sex offenders living there but acknowledge it's a tricky situation as they need to be housed somewhere.
Corrections is reviewing its processes to ensure this doesn't happen again.