The principal of Christchurch Boys High School (CBHS) has responded to reports a student took a photo up the skirt of a female staff member and uploaded a video of another teacher to a porn site.
Earlier on Tuesday, headmaster Nic Hill confirmed to NZME that there had been more than one incident involving cellphones, and that they had been referred to police and online security company Netsafe.
In a statement, Mr Hill said he wanted make it clear that nothing of a lewd nature was circulated.
"That however should not lesen the concerns and seriousness of such behaviour," Mr Hill added.
"Students have breached our standards regarding respect for others, and Christchurch Boys' High School will not stand for this kind of behaviour."
Mr Hill said CBHS was working with the students, their families and providing support for those affected at school.
NZME reported the female worker took leave after the incident, but has since returned to work.
CBHS has also clamped down on phone use at school, instructing parents and pupils that "a clear and specific instruction from a teacher" was now required.
"The teacher is in control of the classroom," Mr Hill wrote to parents.
"This decision has been made after some incidents involving the use of cellphones in class that are contrary to the school values and that do come under the Harmful Digital Communications Act."
Christchurch Police confirmed that a complaint had been received.
"[We] are working alongside the school to ascertain what has actually occurred and who are involved," said Detective Sergeant Daniel Isherwood.
Netsafe would not confirm its involvement.