A high-risk sex offender is living just metres from an Auckland school.

Te Kura Maori o Nga Tapuwae, in Mangere East, wasn't told the convicted rapist was let out of jail last week, and has been in a house just a stone's throw from its grounds.

The Department of Corrections tried to keep the person in secure premises, but a High Court judge turned down its bid for a public protection order.

Officials still believe the man has a very high risk of imminent violent offending.

Arihia Stirling, the principal at the school, claims she wasn't informed by Corrections and didn't find out until Monday, and only then through a member of the public.

"I understand now the enormity and the issues that they were working through but I still felt that we could've worked together on it, instead of being isolated," she said.

The school was so worried it wrote to parents this week urging them to take precautions.

The placement is supposed to be temporary while another property is prepared. The man could be moved today.

Corrections has promised not to place another sex offender in the house again.