A former teacher from Punchbowl Public school has made the series of serious allegations.
She spoke to News Limited anonymously, identified only as Mrs A.
Amid her most concerning claims, she says three years ago Muslim students threatened to behead teachers and bullied other students to read the Koran.
"Students were coming into class demanding to fly the Syrian flag, demanding to fly the ISIS flag. When they were told that they couldn't, they would become quite aggressive and intimidation tactics were used against myself and other teachers."
She claims she and her family received death threats, and at least three other teachers made similar complaints.
But there is no record of them.
New South Wales Education Minister Rob Stokes says an investigation has been launched.
"The point of concern for me about that incident is that the staff member involved did not feel supported or did not feel taken seriously."
Parents with students currently enrolled at the school say they have never heard the claims before.
"No I haven't heard any of that. This is all new news to me."
"No, no nothing." "Doesn't happen?" "Doesn't happen."
"I haven't heard anything."
Punchbowl public is the feeder school to Punchbowl Boys high, which has been at the centre of controversy after its former Principal and his deputy were sacked.
It is believed that was for refusing to implement the state government's community outreach program
Mrs A was also upset that only halal food was served at some school events.
"Ultimately at the end of the day we're a Christian country, we can put that aside and say this is a secular nation. We should not be having one culture or one race dominating the other. I mean it's a secular school, a secular nation, so there shouldn't be any halal in any school whatsoever."
Barrister and Muslim community advocate Bilal Rauf questions some of Mrs A's claims.
"I think there is an element of Punchbowl being unduly targeted. We haven't seen any formal or proper investigation or a report as to the circumstances as to what the situation is on the ground."
Security expert Hussain Nadim agrees, and he takes issue with Mrs A's use of the word 'radicalisation'.
He suggests the word is being used incorrectly, and dangerously.
"I think it's very harmful, partly because this is one of the words we use for hardcore terrorists and suicide bombers in Afghanistan, Pakistan and Syrian. Using the same word for these kids in Australia, kids at the age of 12 or 14, you're pushing them into that corner where there is no return back. I think the term has to be changed. You cannot call these young muslims 'radicals' because you're essentially equating them with someone who's blowing up military forces in Syria."
State education officials visited Punchbowl Public on Thursday morning in the wake of the claims.
But Mr Stokes says there have been no cases at the school of religiously motivated violence.
"The advice I've received is that it relates to one particular incident. There were a number of other allegations made. But from what we can ascertain there's not the incident reports to demonstrate those events."
