A Rotorua Lakes High School student has been suspended after allegedly pulling a knife on another student during a group fight.
A verbal altercation involving 10 boys happened last Thursday and was broken up by two teachers, principal Bruce Walker said.
As the boys dispersed, a student accused a fellow student of threatening him with a knife, but the claim was not reported to the office.
Mr Walker said the accused student was searched the following day and staff found a pocket knife.
The parents of the student were advised by the school to contact the police.
Rotorua Lakes High School received criticism on social media about its actions but Mr Walker said many of the comments online were untrue or "blown out of proportion".
Mr Walker said the school was still investigating the fight but had no qualms about involving police.
"If the victim's mother chooses to report the incident to the police, we will support them in their investigation."
Mr Walker said he was "disappointed" the junior teacher had not mentioned a weapon to the office.
"We take the safety of our students very seriously and have no tolerance for weapons in our school.
"I apologise on behalf of the teacher who did not follow the correct school procedure and have reiterated to all staff how important it is to take any weapon accusations seriously."
Mr Walker said the school and parents of the students involved were hurt by comments made online.
"We have always been very open about the things that happen in our school but we also needed to protect the students involved while we investigated.
"There is no issue with safety in our school that is not faced by every other school in New Zealand. We have procedures in place that work to keep the students safe and I will ensure all staff follow these vigilantly."
The suspended student will return to Rotorua Lakes High School on Thursday.