Corrections is putting extra security around several sex offenders living near schools in South Auckland.
The department has apologised to two schools which were not told about 11 child sex offenders living less than a kilometre away from them for at least two years.
It said it would try to rehouse three of the offenders, but eight would remain at the two Ōtāhuhu boarding houses.
Northern regional commissioner Jeanette Burns said they were able to walk around the neighbourhood, but were closely monitored.
"They're on GPS, and there are exclusion zones which we are notified immediately through the GPS monitoring if they go anywhere into those exclusion zones - which are like schools, and parks - and then we notify police immediately who follow up very very swiftly."
Ms Burns said finding accommodation for the offenders in the tight housing market was Corrections' most difficult job.
She said they were less risk to society when they were housed, rather than homeless.