A high-risk child sex offender who abused a 12-year-old boy was housed a block away from three Auckland schools following his release from prison.

The case has prompted the Corrections Department to reconsider its use of an emergency shelter in Epsom for housing child abusers, and it says future placements will require sign-off from more senior officials.

The local MP, however, is asking why the neighbouring schools were not told about it.

Anaru O'Reilly was jailed in 2005 for indecent assault and after completing his sentence he was housed in Epsom Lodge on Margot Street between late 2016 and May 2017.

The Salvation Army-run lodge is a block away from Epsom Girls Grammar, Diocesan School for Girls and Dilworth School. There are also three other schools nearby.

O'Reilly was on an extended supervision order at the time, a measure which is used to monitor offenders who are considered at high risk of reoffending after their release into the community.

Corrections said he was placed there because he was homeless and there were no other options available at the time.

"Ensuring that offenders have stable accommodation keeps the community safe," said operations director Lynette Cave. "Being homeless increases an offender's likelihood of committing crime."

She said the lodge, which is mostly focused on drug and alcohol rehabilitation, has now been deemed unsuitable for housing child sex offenders and there is no longer anyone with these convictions living there.

The decision to place O'Reilly at the shelter was made by local Corrections staff. Cave said the department had changed its policy to require a district manager to approve a placement of anyone who was subject to an extended supervision order.

O'Reilly left the house in May last year after being convicted of breaching the conditions of his supervision order.

He had left the address and got a job without notifying or getting approval from authorities.

The conditions of his supervision order meant he could not associate with people under the age of 16, could not get a job without consent, and could not stay away from the Epsom address overnight. He was visited twice a week by Corrections staff.

Act MP for Epsom David Seymour said the Epsom Girls Grammar and Diocesan principals had told him they had not been informed about O'Reilly's placement near their schools.

"Obviously they weren't too happy about it," he said. "This is 100 metres away from the grounds of Dio."

Seymour said he wasn't necessarily against sex offenders being placed near schools, but he said that schools and other relevant people in the community should be told about it.

"I have great faith in the Salvation Army. And we are not unreasonable people - [offenders] have to go somewhere. But Corrections needs to let people know."

Diocesan principal Heather McRae confirmed the school was not told about the placement.

"I think it's critical that we are informed," she said.

She supported Corrections' decision to no longer place sex offenders at the Epsom Lodge.

"The schools are so close. And our young people are so precious. We don't want to expose them to any higher risks than we need to.

"I agree that people need the chance to have their lives put back together and to repair the damage within their own lives - without putting at risk other people if we can."

Corrections has been asked for further comment.

Cave said earlier that the department was carrying out a nationwide review of accommodation options for ex-prisoners and the way in which it notifies and engages with the community when housing child sex offenders.