John Weeks, the current headmaster of Knox Grammar, will give evidence at a national inquiry into how the school handles allegations of sexual abuse by teachers.
The Royal Commission into Institutional Responses to Child Sexual Abuse has spent the week examining what happened at the Sydney North Shore private school over three decades when students made allegations against teachers – five of whom were convicted for sex assault offences against boys aged from 10 to 15.
The commission has said there is evidence against three other teachers at Knox.
Evidence this week focused on an incident where a boy was molested in 1988 by a balaclava-wearing intruder who hid under his bed.
Students suspected it was one of the housemasters.
The commission has found no evidence that the matter was ever reported to police or anyone was ever arrested for the break-in or attack.
Mr Weeks will take the stand on Friday after Peter Crawley, his predecessor as headmaster, completes his evidence.
Also expected to be called on Friday is Robert Wannan, former chair of the Knox Grammar School Council and Stuart Pearson, general duties master at Knox, who investigated the balaclava incident.