Three students have been expelled from an Otago high school after assaulting another student in a school bathroom.
The incident at Otago Boys' High School was filmed and widely circulated on social media.
The attack occurred last Wednesday and police were also investigating.
It was reported the cellphone video showed a defenceless student being cornered and repeatedly punched, kicked and shoved.
At one point it appeared he offered his wallet in an attempt to placate his attackers.
Otago Boys' High School acting rector Andrew King this afternoon confirmed the three students had been permanently excluded following a disciplinary process involving the school's board.
The victim had returned to school and was being offered support.
"The school is assisting the police inquiry into the incident and also actively investigating to identify those who have shared the video," King said.
"It is working with New Zealand's online safety organisation, Netsafe, to remove the video from social media and restrict further harm caused by its distribution.
"Students are aware of the school's zero tolerance for unacceptable behaviour in the school environment and its policies on bullying and digital safety. Earlier this year, an additional digital safety policy was introduced to ban the use of phones during the school day. Phones must remain switched off and students are aware that there are immediate consequences if they are caught using their phones.
"The incident has highlighted the need for strict regulations relating to the use of digital devices and the school will continue to respond with all its authority to protect students' emotional and physical safety.
"In the past year, the school has increased its counselling staff, instigated an improved rostering system to enable more staff to be circulating around the school, and introduced an online anonymous reporting system.
"The student who was assaulted has returned to school where he is being supported by counsellors and other students."