Sydney's prestigious Cranbrook School has issued an apology for "past failings" following a review into its handling of any child safety issues over the past 15 years.

The independent review was announced in March after the ABC's Four Corners revealed former headmaster Nicholas Sampson had kept a teacher on staff, and went on to promote him, despite knowing he had sent multiple graphic emails to a former female student at a Catholic girls' school where he had previously taught.

Four Corners also exposed allegations of a toxic culture and raised questions about the treatment of female staff, ahead of its move to go co-educational in 2026

Mr Sampson resigned days after the broadcast.

Just three days after that, the school announced the external review which was looked into any concerns the community had, including child safety issues.

It was conducted by the law firm Thomson Geer, working alongside educator Amanda Bell and invited people to submit their concerns through an online whistleblower platform.

'Some issues involved events going back decades'

The school said 76 reports were made by current and former students, parents and staff from April to July. 

Of the 76 reports, a handful were related to child sexual abuse.

It said some reports were positive but the majority were not.

In a statement, Cranbrook School Council president Geoff Lovell said some concerns raised during the review were not known to the school, others were.

"The majority of concerns were raised by current and recent former students, parents and staff. Some issues involved events going back decades."

The statement did not say how many of those concerns involved child sexual abuse, but it did say that none of that nature were about current staff at Cranbrook.

It said each report was responded to on a case-by-case basis and that it has addressed the vast majority, with a small number still ongoing.

"The school acknowledges that not everyone who has participated will be satisfied with the school's responses," the statement said.

Respondents thanked for their 'courage' 

Mr Lovell thanked those who made reports for their "courage" and said he "recognises the lasting and damaging effects that abuse has on those who suffer it, and those around them".

He said those who have reported abuse have been offered support.

The review by Dr Bell also suggested several areas where the school can improve to protect students and staff, which the school said it was "actively addressing".

The school said it:

• Has updated its whistleblower policy to maintain an online reporting system for complaints
• "Continues to strengthen" its Child Safe framework so it is in line with best practice
• Is expanding its student wellbeing and pastoral care program
• Is strengthening programs and resources to "better meet the needs of its diverse school population"
• Is reviewing its student bullying and harassment processes and policies, including more opportunities to raise concerns through surveys and targeted education programs
• Is introducing a new "respectful relationships policy" and providing "intensive" professional development sessions for staff to "establish and maintain a respectful, safe and inclusive workplace"
• Is reviewing its processes and policies on staff bullying and harassment

Mr Lovell said the concerns raised by the respondents "provided a valuable opportunity to reflect on how they can improve the wellbeing of its staff and students".

"The school sincerely hopes that … those most affected have renewed faith in the school's ongoing commitment to a positive, safe and respectful environment and culture."