"This includes the requirement for employees to have a police check. Those working at the Saturday music school have not had a police check. We are suspending all Saturday music lessons until this is put right."
The school was told this week by one "concerned person" that someone who relieved on a small number of occasions in the music classes would not have passed a police vetting process.
"This was said to be because of previous convictions for serious sexual offending. The person who raised this concern has provided us with the name of a known offender who they suspect may have taught music at the Saturday classes. We have not been able to confirm at this stage whether they have taught at the music school or not or to positively identify them by the name they used."
Fenton said the suspicions had been reported to the police and the Ministry of Education, and the school has obtained legal advice and advice from the School Trustees Association.
"The Board expects the police to investigate whether the concerns passed on to us have any substance - that is, whether at anytime a person of that background was associated in any way with the Saturday music school, even as an occasional reliever," she said.
"At this stage, given the lack of clarity resulting from the informal arrangements we are not proposing to give the name wider publicly."
Fenton confirmed anyone teaching at the Saturday music school had not been through the police vetting process.
"Other than the one person who has raised the matter of one individual possibly being employed no one has at this point raised any concerns of this nature with Island Bay School about the Saturday music school."
The school has changed its procedures so this does not happen again, Fenton said.
"Our record keeping at the Saturday Music School has not been sufficiently robust to allow us to directly identify all the relieving teachers. In future, full employment records will be kept."
The school's weekday staff have been vetted, as have parents attending school camp.
Fenton said the safety and security of the children was "paramount".
"I understand that this information is worrying. If you are concerned about how to discuss this, if you wish to, with your child you can talk to the principal and she can give the appropriate supports available."