Widespread child sexual abuse at the prestigious private boys school Knox Grammar was covered up for decades because the school was more concerned about its reputation than the welfare of students, a royal commission has been told.

On the first day of the public hearing into how the school dealt with sexual abuse allegations,fresh claims were made against three former staff members. A further five former staff members have already been convicted of multiple sexual offences against students.

An unnamed solicitor had recommended the destruction of documents at Knox Grammar school. Credit:Jon Reid

Former assistant headmaster John Rentoul wept as he told the Royal Commission into Institutional Responses to Child Sexual Abuse about the discovery his son, David, was molested by Knox music teacher Barrie Stewart in the late 1970s.

Mr Stewart, along with other teachers, continued to work at the school despite numerous claims about inappropriate behaviour with students.