And in the past decade, 66 teachers have been found guilty of sexual offences, while many others have been suspended following charges.

Victims have spoken out in the wake of a state parliamentary inquiry and the ongoing Royal Commission into Institutional Responses to Child Sexual Abuse, leading to fresh investigations.

Last financial year, 10 teachers found guilty of sexual offences were deregistered and a further five teachers were suspended following charges, according to Victorian Institute of Teaching records.

Just two teachers were disqualified in 2006.

Former teacher Salih Dervish was convicted in February after he was found with 4320 child pornography images and videos, which the judge described as "repulsive".

Among the images were photos of former students in sexual poses and wearing the uniform of the secondary college where he had worked for 12 years.

While ex teacher Melissa Bonaddio was struck off the register after she was convicted of two counts of an indecent act with a 16 or 17-year-old child under her care.

Another teacher, Wesley Ellis, pleaded guilty to penetrating a 16-year-old student who had confided in him while her father was dying, a court heard.

Former Ivanhoe Grammar teacher Graeme Harder was jailed for five years after having a sexual relationship with a student, whom he exploited through the lure of trips and outdoor activities. While ex-Berwick Secondary College teacher Marinko Jankovic used a pen camera to film under the skirts of students.

Linette Harriott​, manager of community training and helpline at Child Wise, said callers to the national hotline still alleged offenders in schools were not being reported to police, while victims were not offered counselling.

"We get calls on the helpline from parents who have been distressed when children come home and tell them things that are happening in school, yet the school is not being particularly decisive in relation to the incident in reducing or removing the risk."

Jason Newman, an Australian and New Zealand Education Law Association committee member and principal at law firm Gilchrist Connell, said the royal commission had prompted victims and witnesses to speak out.

He said schools were much more aware of child abuse and working hard to reduce risks.

"It's much more likely to be reported now than 20 or 30 years ago," he said.

Australian Children Foundation chief executive Joe Tucci​ said that while some schools were doing great work in stamping out abuse and employing child safety officers, others lagged.

An Education Department spokesman said all schools must have policies to protect the safety and welfare of students.

"This includes a current obligation on all teachers and principals to make a mandatory report if they have reasonable grounds to believe a child has suffered, or is likely to suffer, sexual abuse," he said.

From next year, the Victorian Registration and Qualifications Authority will monitor school compliance with new child safe standards that resulted from the Victorian inquiry into child abuse.