Principals want the power to search students' cellphones and laptops to combat cyber-bullying.
The call comes as part of a change in the way schools deal with the problem, with principals shifting away from restorative justice to suspending bullies.
Secondary Principals' Association president Patrick Walsh said principals were being forced to take a heavier hand to ensure student safety, on the back of a backlash from parents, who say soft approaches don't work.
The association is working with the Ministry of Education to give principals the power to confiscate phones, laptops and digital devices.
"Cyber-bullying has become so common and the consequences so serious, that it overrides privacy concerns," Walsh said.
Search and seizure guidelines were developed last year to allow principals to search students for drugs and weapons, but principals want it written into law.
"To discover evidence of cyber-bullying or other inappropriate behaviour, it would be a necessary extension to search and seizure powers."
One in five children now suffers from cyber-bullying. "The effect is devastating, ranging from not being able to sleep through to self-harm."
Netsafe executive director Martin Cocker said cyber-bullying was more difficult to tackle than traditional bullying because it was not as visible. Giving principals access to the technology used to bully could help combat the problem.
"If a student brings a mobile into school and uses it during the day, the school should be within its rights to view it," Cocker said.
A ministry spokesman confirmed Walsh had provided advice to officials but said no decisions had been made.
The association also wants to get tougher on schoolyard bullies, and be given the power to discipline students caught outside school. "If we catch them outside the gate, whether it be videoing a fight at the park or smoking at the dairy, we want to be able to deal with that."
Walsh said schools had no authority to discipline students caught outside their grounds but some parents could no longer control their children, and police did not have enough resources. "Some parents are unable or unwilling to exercise the control of their children, so it falls on the school."
His concerns come on the back of damning reports from the ombudsman about sexual and physical assault at some schools. He said parents had a right to feel their children were safe at school, and they wanted the bullies expelled.
But Massey University researcher Anne Ryan, who has studied bullying, said neither the restorative justice nor punitive approach would eliminate the problem.
"There is a real danger of a blame culture. Not just the bully, but the victim, is seen to be responsible. They carry the burden to fix the problem. We're going nowhere, so the students, teachers and parents are getting frustrated."
Although there was no simple solution, she said more research was needed into how the school system might be reinforcing student power struggles. "Bullying is a reflection of that power operating within schools."