Five of the accused Knox Grammar teachers have since been convicted of child sexual abuse offences, relating to crimes committed between 1970 and 2009.
Counsel assisting the commission David Lloyd told yesterday's Sydney hearing evidence would be presented against a further three teachers, who had not been criminally charged.
The commission will also hear evidence the Uniting Church school deliberately destroyed a number of files containing students' allegations of abuse.
"It is anticipated that there will be evidence that on no occasion between 1970 and 2003 did Knox report any allegation of child sexual abuse to the New South Wales Police."
Barrie Stewart, who received a suspended sentence for abusing seven children, was "notorious amongst the students for being a 'toucher' of young boys", the commission heard.
Mr Lloyd said teacher Craig Treloar would regularly show students heterosexual, homosexual, underage and bestiality pornographic videos before asking boys to perform sexual acts upon him.
He said then-principal Dr Ian Paterson was told of the allegations during the 1980s but allowed Treloar to continue teaching at the school until his arrest in 2009.
The hearing is expected to last a fortnight.
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