Furious parents and old scholars of Trinity Grammar School in Melbourne's east have confronted the school council at a special meeting on Friday night, after the college's long-standing deputy principal was sacked for trimming a student's hair on school photo day.

More than 800 people attended the meeting on the eve of a long weekend and more than 1,600 had signed an online petition calling on the school to "Bring Brownie Back".

Council's chairman Rockerick Lyle sent a letter to all parents and members of the school community, informing them that "the handling of a disciplinary issue by Mr [Rohan] Brown … was in contravention of school policy and was also inconsistent with community expectations in this day and age".

"As a result, the School Council was of the view that Mr Brown's leadership position at the school was no longer tenable," he wrote.

"We are all disappointed and deeply saddened by the situation."

A former Trinity Grammar student who attended the meeting said that the boy whose hair was cut did not want Mr Brown dismissed and that the boy's family had not made a complaint.

More than 800 parents and former students came to a meeting on Friday night, with many angered by the school's stance. ( ABC News )

'This is like losing Dumbledore'

A former board member of the Trinity Old Grammarians Association, who wants to remain anonymous, told the ABC that Mr Brown's dismissal was part of a "much bigger power struggle".

He believed Mr Brown was the "last hurdle" standing in the way of those who wanted to change the school's vision and direction.

Rohan Brown had been at Trinity Grammar School since 1987. ( Supplied: Trinity Grammar )

He said Mr Brown had been at the boys' school in Kew since 1987 and was so well respected that Year 12 students had threatened to boycott classes and hundreds of students sang protest songs against his sacking at lunchtime today.

"They're shattered … apologies for using a Harry Potter analogy, but this is like losing Dumbledore," he said.

"This will backfire on the school leadership."

The former board member said Mr Brown was personally shattered by his sacking.

"The school was his life. He worked 100-plus hours each week, he's the heart and soul of Trinity Grammar."

"He embodies what the school is about, raising well-rounded young men as opposed to the best and brightest, it's all about community service."

In a statement, the school said it set up the meeting because it understood "the impact" the recent decision had had "on some quarters of our school community".

"The school's council and executive is reflecting on the views presented," the statement said.

"We expect teachers to role-model the right behaviours and whenever there is evidence to the contrary, it's incumbent on us to investigate."

Sacking 'a total shock to everyone', parent says

The former board member said the student who had been given the haircut had been previously asked many times to trim his hair and it "certainly wasn't a sackable offence".

"[Rohan Brown] was the Head of the Senior School and the disciplinarian. When I was at school he'd tell me to shave … I had a love-hate relationship with the guy, but I have nothing but respect for him," he said.

A parent at Trinity Grammar, Philip Robertson, told ABC Radio Melbourne that the sacking was "a total shock to everyone".

"The letter only said that it related to a disciplinary action he took involving one of the kids, so I'm a bit concerned that it was relayed in that way because it sounded as if something terrible might have happened," he said.

"Rohan [has been] at the school for 30 years, cutting a student's hair that's too long … might be out of line with current standards but it just seems a bit extreme what's happened," he said.

"There's a lot of people who would suggest the culture of the school rests with him, there's been quite a turnover of staff in the last few years and a lot of people feel that Rohan has carried the flag of the school.

He's old-school but I don't think he's too strict, he's very popular with the kids and parents and I think there's a lot of people who'll be devastated by this news."

A Facebook page calling itself "Culturally Concerned TGS Community" says many people have expressed their concern and shock about Mr Brown's removal.

The creators of the page have also organised a Town Hall meeting next Tuesday, to show support for Mr Brown and "to take a firm stand to protect the legacy of the school and its proud 114 years of history".

Trinity Grammar School's headmaster, Dr Michael Davies, did not respond to the ABC's requests for comment.