Political opinions are split on the scale of the potential problem of schools seeking payments from parents seeking out-of-zone enrolments for their children.

An investigation by the Office of the Auditor General's identified five schools, all in Auckland, that have been involved in the practice.

Rules forbid such fees being levied, though voluntary payments can be asked for.

Minister of Education Nikki Kaye said she's reasonably confident from the advice she's been given the problem isn't widespread.

"It's a small number of schools. That's all the advice I've had, that we're not talking about a large number"

But Labour MP Chris Hipkins isn't convinced the problem is as limited as the Minister thinks, given the Auditor General's investigation did find additional schools breaking the rules.

"It's quite possible that had the sample size been larger they would have unearthed more schools."

Five Auckland schools have been identified as asking for payments in such cases - fees and charges are not allowed under current rules, although voluntary donations can be sought

Mr Hipkins said any parent that's paid a fee for their child, or children, is absolutely entitled to ask for the money back.

"The schools simply can not require it and the schools nee d to comply with their legal obligations not to try and charge parents fees."

Ms Kaye said that what is important to her is that parents and schools are really clear that enrolment is free in New Zealand.

"It's clearly unlawful to charge a fee for out-of-zone ballots"

She said that her Ministry will be issuing further guidance to schools to clarify that asking for donations in such cases is improper.