Ballarat Grammar says it has assisted a number of former students to report allegations of historical sex abuse at the school to the police and the child abuse royal commission.
The Anglican school's headmaster Adam Heath said the school wrote to former students late last year asking them to come forward if they had experienced abuse in the past.
"The school decided to be as proactive as possible," he said.
"That was really a measure by the school to do everything possible to offer support to any former students who had been subjected to abuse."
Mr Heath said a number of students had since approached the school, to report instances of abuse relating to the 1970s and early 80s.
"Our reaction in that situation has been to help them to make a report," he said.
"In some instances they've sought the support of the school. In other instances they've sought the support of the Anglican Diocese.
"In other instances again I'm aware that people have gone directly to the the police."
Mr Heath confirmed some of the abuse reports related to a former reverend at the school, who died in 2000.
"There's some victims who relate to that ... alleged perpetrator," he said.
"And then there's others who have mentioned allegations directed at other people.
"The substantiated claims are of a very small number, but there may be other victims that come forward in the future and we're here to support them in every way that we can."
Mr Heath offered to apologise to former students who had reported abuse at the school.
"I've been very keen wherever possible to do that in person, just to convey the sincerity of the school's regret," Mr Heath said.
The school has not featured in the Royal Commission into Institutional Responses to Child Sexual Abuse's previous public hearings on Ballarat, which until now have focussed on Catholoc schools and institutions.