Specialist detectives are reviewing the material, which reportedly included racist and homophobic videos and references to violent misogyny.
Principal Scott James wrote to parents today outlining the consequences handed down to the students involved.
They ranged “from suspension to students leaving the school”. The cost to attend Knox is $35,000 a year for year 12 students.
“The boys posted inappropriate images and engaged in offensive commentary in an online private chat room,” James wrote.
“The nature of these posts is contrary to the values and culture of Knox and is unacceptable.
“The actions of these boys do not reflect a Knox education or the expectations that we place on our students to be respectful and responsible citizens in the community.”
He said some of the images shared were “taken during school activities and later doctored”.
“To be very clear, the doctored images do not require mandatory reporting under child protection requirements, and we have discussed the matter with police,” James said, adding that all students involved had been counselled and the families of identifiable students had been spoken with.
Child abuse and sex crimes squad commander Detective Superintendent Jayne Doherty said the specialist detectives were reviewing material provided to police.
“Police will continue to review activity, make inquiries and will work with the school, parents and the eSafety Commissioner in relation to any matters that arise,” she said, in a statement.
James said he believed the school had found the right balance between “upholding the values of this community and the need for consequences” and said it was a reminder about social media education.
“I ask that you speak with your son about his use of social media platforms and the need for him to always act respectfully and sensibly whether online or in person,” he wrote.