Music lessons have been suspended at a Wellington primary school - after fears children may have been taught by a convicted sex offender

Island Bay School says the person sometimes filled for a regular teacher at the Saturday music school.

They were only made aware of the possible history of serious sexual offending when someone raised concerns.

The school says music teachers are managed informally and haven't undergone police checks.

Principal Deborah Fenton admits that's the wrong approach to take and the school has since changed their procedures.

The school's board expects the police to investigate whether the concerns have any substance.