The Royal Commission into Institutional Responses to Child Sex Abuse announced on Thursday that it would conduct a wide ranging public hearing into how the school, located in Wahroonga on Sydney's upper north shore, had responded to inappropriate conduct by teachers towards students between 1970 to 2012.

This would include:

• The experience of sexual abuse of former students at Knox Grammar;
• The response of the school and the Uniting Church to concerns about inappropriate conduct, including investigations and subsequent and criminal proceedings;
• The systems, policies and procedures in place at Knox by which sexual abuse concerns were raised and responded to  since 1970; and
• The regulatory system governing Knox's response to allegations of child sexual abuse by its employees.

Knox Grammar has been the scene of multiple instances of child sexual abuse, particularly in the 1980s.

These included the indecent assault of four students aged 11 to 13 by former teacher Craig Treloar between 1984 and 1987.

In 2009 and 2010, Treloar, Adrian John Nisbett and two other teachers pleaded guilty to abusing students.

Some had continued to teach at the school for decades after the attacks took place.

They received a range of punishments, including in Treloar's case an extended jail sentence.

The school was sued for $1 million for allegedly breaching its duty of care to one of the victims of this abuse.

In a letter sent to Knox Grammar old boys on Thursday, Headmaster, John Weeks said the sex abuse incidents had been widely publicised in 2009 and Knox had "always accepted its responsibility in this matter".

Mr Weeks went on to say that the school had "sought to support, firstly the police enquiries and, most importantly, any students who were identified as having been sexually abused".

"Knox has a most comprehensive child protection policy covering staff selection and training, student awareness and support structures..." Mr Weeks continued.

The public hearings are due to commence in Sydney on February 23.