The Kings School headmaster has written of his deep regrets regarding the Knox sexual abuse inquest.

The headmaster of elite boys’ school Kings has written a heartfelt letter to the parents of his students, telling them of his regrets during his time as a teacher at the prestigious boys school Knox Grammar School, in Sydney’s north.

In the letter, headmaster Tim Hawkes also apologised for his comments at the recent Royal Commission into Institutional Responses to Child Sex Abuse.

The Kings School headmaster, Tim Hawkes. (Photo: The Kings School/Facebook)

Mr Hawkes appeared as a witness at the royal commission, and later told the media he had no regrets about his actions 30 years ago when he failed to report the sexual abuse of a young boarder.

Related content: Knox Grammar – a legacy of shame, angst and depression.

He has since written to parents apologising for his insensitivity.

Fairfax Media reports Dr Hawkes said he has “thousands” of regrets, and told of wanting to go back and change these moments.

Knox Grammar School has been the subject of a Royal Commission into Institutional Responses into Child Sex Abuse.

Fairfax Media obtained a copy of the letter, which reads:

The hearings are looking at the way Knox Grammar handled complaints of inappropriate conduct by teachers over more than 30 years, between 1970 and 2003.

Related Content: Knox Grammar: A legacy of shame, angst and depression.

Last week, the inquiry was told five Knox teachers had been convicted of child sex offences, and there was evidence three other teachers were involved in inappropriate conduct, ABC News reports.

The royal commission will complete its work in December 2017 and provide recommendations to government.