Police were also at the school to ensure students knew how to report any allegations.
In a statement, Canterbury district crime manager Detective Inspector Greg Murton said police were “concerned” by the survey’s findings, “particularly the allegations of rape and sexual assault”.
Murton said police had worked with Christchurch Girls’ High School since students staged protests in March, meeting with them to “discuss the issue and provide a pathway for any complaints of criminal behaviour”.
Children's Commissioner Andrew Becroft has called for “urgent action” on consent and gender equality education for boys.
The survey, conducted by researcher Liz Gordon, said it was possible some of the individual rapists had committed the same acts before or since.