The school tradition of staying with family billets while on sports exchanges is under threat, the secondary principal's association says.
Association president Patrick Walsh said he had been contacted by several schools worried about the implications of new health and safety legislation and the Vulnerable Children's Act.
"There are a number of principals and deputy principals that have raised with me the fact that they are either considering cutting back on, or stopping altogether, sports and cultural exchanges on the basis that they think those two acts require them to police vet billets."
Mr Walsh said police vetting was impractical and costly, meaning schools were considering cancelling exchanges.
Earlier this month, Devon Intermediate in New Plymouth called off its annual sports exchange with Rotorua's Mokoia Intermediate.
Under the headline "Sports Billeting" in the school's newsletter, Devon Intermediate cited concerns over the Health and Safety Act and cost of alternative accommodation.
"Unfortunately with the changes to the Health & Safety Act, we will not be hosting our fellow students from Mokoia this year.
"The changes meant that we could no longer billet students, and the Mokoia staff and students would have to stay elsewhere meaning the cost would be too much."
Devon Intermediate associate principal Conrad Hailes said Mokoia set the cancellation in motion when - for the first time - it insisted billets were police-vetted.
"We received notification from Mokoia Intermediate that they would require us to fill out police vetting on our families for the billeting situation for the sports exchange. So from that point of view, we didn't have time to do that before the sports exchange actually took place."
Mr Hailes said the students involved were gutted the exchange was not going to go ahead.
"When we talk to students who have left the school and come back years later, they always remember their billets and that time and quite a few of them remain quite close with those billets. So it's not just a three day visit, it extends beyond that in terms of friendships and connections that they have built with the students of Rotorua."
Mr Hailes said Devon, which did police vet volunteers for its school camps, would now be reviewing the exchange with Mokoia to see if it had any future.
Mr Walsh said there was no legal requirement for volunteer billets to be police vetted, but schools were taking a safety first approach because they were worried about their liability and potential risk to students.
The fears were putting in jeopardy a system that had worked well, and provided rich experiences for young people for decades, he said.
"I would just err on the side of caution and advise principals to think very carefully about it, because the billet situation is one that provides a wonderful experience for the young people in schools, and it's something I wouldn't want to see diminished because people are being overzealous in the checking."
Mr Walsh said the principals' association would be raising the issue at a meeting with Ministry of Education next week.
The ministry's head of sector enablement and support, Steve Stuart, said the safety of children was of paramount importance to the ministry, and to every school.
Mr Stuart said the Vulnerable Children Act 2014 (VCA) made sweeping changes to protect vulnerable children.
"It requires state-funded services and their contracted providers to safety check - vet and screen - the children's workforce, and have child protection policies to ensure those who work with vulnerable children are safe and competent.
"Those who work with children will also need to have their checks updated every three years while their employment or engagement continues."
But Mr Stuart said this did not extend to volunteers.
"Parents who volunteer to help out at school events are considered to be volunteers under the act. Volunteers, as unpaid workers, are not required to be safety checked under the new VCA requirements.
"We do, however, encourage schools to safety-check volunteers who are likely to be alone with children, with guidelines for safety checking of volunteers available on the Children's Action Plan website."
WorkSafe, the agency which administers the Health and Safety in Work Act, said there was nothing in the act that required schools to police vet volunteers involved in an out of classroom experience, such as a school sports or cultural exchange.
WorkSafe said it would be a policy decision for individual schools.