The former headmaster of Sydney’s Knox Grammar School “failed to prioritise the welfare of boys over the reputation of the school” by covering up allegations of child sexual abuse, a royal commission has found.

The report on last year’s hearing at the Royal Commission into Institutional Responses to Child Sexual Abuse examining Knox Grammar was released today.

The 2015 hearing also looked into the experiences of 12 survivors, as well as the response from the school and the Uniting Church of Australia, to concerns raised about several teachers between 1970 and 2012.

At the hearing, Dr Ian Paterson said that during his 29 years as headmaster he was only aware of one instance of sexual abuse involving one teacher.

However, the royal commission found that was “clearly incorrect” and that Dr Paterson was also aware of allegations in relation to three other teachers, as well as an affair between a teacher and a student, and an incident where a boarding school student was sexually assaulted by someone in a balaclava.

“During Dr Paterson’s time as headmaster of Knox, his attitude and the culture he fostered at the school were dismissive of allegations of child sexual abuse,” a statement from the royal commission said.

The royal commission also discovered Dr Paterson provided misleading and positive references for three former teachers who left the school after child sexual abuse allegations were made.

All three teachers went on to obtain employment at other schools.

Former headmaster ‘deliberately withheld information’ from police

The first time New South Wales Police had an inkling of any of the abuse was in 1996.

Inspector Elizabeth Cullen met with Dr Paterson to discuss anonymous information she had received about sexual abuse allegations relating to five teachers.

Dr Paterson told the royal commission he accepted that at the time of this meeting he would have known about several incidents and suspicions relating to some of his staff.

The commission’s report found he “deliberately withheld information from Inspector Cullen”.

“Instead, he allowed her to have access to files which Dr Paterson knew did not contain any information about those matters.”

It was not until former students began reporting their experiences to police in 2009 that charges were laid.

Five former teachers — Roger James, Adrian Nisbett, Damien Vance, Craig Treloar and Barrie Steward — were charged and convicted of sex offences against former students.

Former housemaster ‘failed to act’ in boys’ interests

The report also mentions the current headmaster of The King’s School at Parramatta, Dr Timothy Hawkes, who was previously a housemaster at Knox Grammar.

In November 1998, a 14-year-old boarding school student was sexually assaulted in his bed by someone wearing a balaclava, but police were never told about the incident.

“Dr Timothy Hawkes, who was the housemaster at MacNeil House at the time of the incident, maintained that he believed the police were called,” the report said.

“We reject that evidence.”

The royal commission found that as the person who was “responsible for the welfare and pastoral care of the boys who resided in MacNeil House”, Dr Hawkes ought to have notified the police or at least properly satisfied himself that police had been called, but he failed to do so.

“We find that both Dr Hawkes and Dr Paterson knew that police had not been called.”

In a statement, Knox Grammar headmaster John Weeks said the school fully supported the report’s commentary and findings.

Mr Weeks said the royal commission had been very important for survivors.

“In 2009, the School and the Uniting Church issued an unconditional apology to the survivors and we have since been working together on redress,” Mr Weeks said.

“We remain deeply sorry for the pain and suffering inflicted on these men in their childhoods, and commend them once again for their courage in coming forward.”