The school principal, whose daughter was one of the victims, said she had been in contact with Minister of Education Anne Tolley to recommend that the Government introduce an accreditation system for private school camps.
Ms Tolley had replied it was up to individual schools to check whether camps were following the ministry's guidelines.
"I've always been under the assumption that anyone advertising themselves as a school camp must have some kind of link with the ministry. If they can advertise themselves as being available for school camps I would have thought that there would have been some regulations around that,'' the principal said.
"Nobody's monitoring them and that's the problem. They're leaving it up to individual schools to make sure that they get those contractors to fill out a form to verify that they've got good procedures in place for employing staff but nowhere on that form... does it say `have you police vetted your staff'.''
"It would be so much easier if the ministry actually took responsibility for that.''
Labour's education spokeswoman Sue Moroney said if schools were the responsibility of the ministry then it was their responsibility to run checks on the camps.
"School camps are part of the school experience - they're not divorced from it - and to me it's irresponsible of the Minister of Education to say `nothing to do with me'.
"If I was the minister of education I would have a serious look at the legislation to make sure that it is robust enough to protect our school children because they should never be put in this sort of situation: a sex offender working directly with children - that's what the legislation is designed to prevent.''
In a statement, Ms Tolley said: "This incident is very concerning, and the safety of students needs to be an absolute priority for schools when organising trips.
"Education Outside the Classroom Guidelines are an excellent resource for schools, and aim to help boards of trustees, principals, and teachers to provide quality educational experiences, including guidance on the selection and screening of volunteers and contractors.''
The principal, who cannot be named to protect the victims, said what had happened was every parent's - and principal's - worst nightmare.
"I don't think I can ever describe how it felt. I guess as a principal I am always aware that I could have children disclose something to me, and to have one disclosure is hard enough. To have that number is unbelievable.''
Her daughter, who had her birthday the day she was sexually assaulted, had gone through a long period of wanting to be by herself and being frightened when she went to bed at night.
It had been helpful for the victims to sit behind Everson when he was sentenced in court yesterday, she said.
Everson's lawyer, Roger Gowing, asked that Everson be given a finite jail term and be the subject of extended supervision on his release from jail.
Justice Lang said preventive detention was the only way of protecting the community from Everson.