The footage continues for about 16 seconds before anyone steps in to stop the attack.
A concerned mother, who wished to remain anonymous, said it was one of many violent attacks she knew of at the school. She believed violence had increased dramatically over the past two years.
"A boy confronted a gang member after his bike had been stolen.
"What started as a one-on-one fight over the stolen bike, turned into a savage beating of an innocent pupil," she said.
Preece said that violence at the college seemed to be at Year 9 and 10 level.
"Our students don't like violence and if you look closely you will see a couple of lads trying to drag a mate out of the scrap, because they are aware that such incidents are treated very seriously by our board of trustees.
"There is no gang problem at our school. We have a handful of students from families with gang backgrounds, out of 1200 students, and they respect our school as a place that they can get on with their learning.
"None of the lads involved are gang members or are from gang households."
He confirmed the fight was over a stolen bike.
Preece said the school had a number of programmes that target problems, including culturally responsive and relational pedagogy, Positive Behaviour for Learning, and restorative practice.
"We also have 24/7 youth workers to support our students," he said.
Ministry of Education deputy secretary Katrina Casey said this week that it had spoken to the principal and was satisfied the school was taking this matter seriously and had appropriate systems in place.
