Schools in Otahuhu appear to have been kept in the dark about a large number of sex offenders living the area.

It is understood up to 16 sex offenders are thought to be living on a single road in the south Auckland suburb. 

10 are believed to be in one boarding house.

The news has left schools reeling to know that the offenders are living in close proximity to children.

Mt Richmond School principal Kathy Dooley understands 10 offenders are living in a single boarding house.

She told Newstalk ZB Corrections didn't contact the school before the offenders were placed in the area.

It's understood at least two offenders triggered GPS alerts this week after being too close to schools.