Residents in a northwestern Auckland suburb are horrified that a child sex offender was living in their midst without them knowing.

Residents became aware of a property in Massey where offenders placed by the Corrections Department were living this month after police were called to deal with someone behaving suspiciously.

The department considers whether to notify communities of an offender on a case-by-case basis and in this situation decided against it  because the person was living at the property on a short-term basis.

But Colwill School principal Robert Taylor is upset he wasn't contacted.

''I'm not impressed. We have a lot of children living in the area and several schools will be impacted by the placement.'' 

A grandmother living near the house says she "felt sick" when she heard the news and is upset residents were not consulted.

"We wouldn't have known if the police didn't come that day. People don't know whether they should lock up their kids. I know these people all have to go somewhere but we should have been told." 

 Corrections Department staff visited the resident after being contacted by Fairfax Media.

"I told them I was disgusted that our backyard, the only place where my grandkids should be guaranteed  safety, wasn't safe any more."

Corrections Department acting regional manager Alastair Riach said a significant amount of  preparation goes into approving a suitable address for a child sex offender.

"This includes checking the property as well as conducting a visual check of the neighbourhood for signs of children residing nearby, proximity of the house to parks, schools, kindergartens, swimming pools, libraries, thoroughfares and other places frequented by children.  

''An address would not be approved where it was considered that there was an undue risk to the safety of the community." 

Riach said community notification is considered in line with the Privacy Act.

"In this instance a decision was made not to notify neighbours initially, as the accommodation arrangement was considered to be of a short-term nature.''

Taylor said that was a poor excuse.

Riach says neighbours have now been consulted because of concerns raised.

''We are unable to comment on the offender's specific circumstances as the matter is currently before the courts. However, we can say that we are working closely with police to manage the situation."

- © Fairfax NZ News