Sam Leishman was only 12 years old when sexual abuse began at the hands of his teacher at New Town High School in Hobart in 1978.

"I had a very difficult time at school when the other kids, my peers, found out about it," he said.

"Teachers, I suspect, had an idea of what was going on as well."

With the abuse beginning at the end of grade seven and continuing into grade eight, Mr Leishman thought he was the only one being targeted by his teacher.

Unfortunately, he was wrong.

Darrel George Harington, 68, has since been jailed for the sexual abuse of boys in the 1970s, 80s, and 90s.

"It's pretty horrifying, yes, and I've been naive about the whole thing," Mr Leishman said.

Documents from the Department of Education showed numerous complaints were made about Harrington and he was moved from school to school, even being transferred to a girls school to limit the risk of him continuing to offend.

"What hasn't happened is the answers to the questions and the deeper investigation into what went wrong and how this was allowed to fester on for all these years," Mr Leishman said.

Lawyer Sebastian Buscemi, of Angela Sdrinis Legal, is representing Mr Leishman and at least one other survivor of Harrington's abuse in suing the state for negligence.

Mandatory reporting was introduced in Tasmania in the late 1970s.

He said records indicate that Harrington taught right up until 2002.

"His victims in the late 70s and the 80s, in the 90s, and into the 2000s would never have existed because he would have not been a teacher, and potentially have been sentenced to a term of imprisonment but instead, he was allowed to continue," he said.

He is also acting for six survivors of abuse by another Tasmanian paedophile teacher and former priest, Anthony Le Clerc, who are also preparing to take the state to court.

Mr Buscemi said questions need to be answered about how this abuse was allowed to occur.

"It's completely beyond the pale, or what I think any Tasmanian or Australian would think a Department of Education would do in one of those instances, let alone repeatedly with at least two teachers," he said.

Le Clerc was transferred between four schools in Tasmania's north-west when complaints were made about him.

He was jailed in 2015 for molesting 14 children between 1973 to 1983.

Other abuse survivors to make claims

It is alleged Tasmania's Education Department protected up to 10 child-molesting teachers.

Mr Buscemi is preparing civil claims by at least seven survivors of abuse to be lodged in the Supreme Court.

"It actually took me a little bit of time to actually twig that that's what was occurring, because it just seemed so out of place for an education department to be doing that, let alone over such a long period of time, with such senior officials within the department involved," he said.

"There are indications that there were more, but we don't have the documentary evidence that we do on two of the higher-profile ones," Mr Buscemi said.

Mr Buscemi said survivors were being forced to sue to make Tasmania's Education Department explain in court why it moved two paedophile teachers from school to school, allowing them to continue to abuse children, rather than sacking them.

Sam Leishman said he tried other ways of getting the answers he needed for the Education Department.

Instead, Mr Leishman was asked to fill out a freedom of information request, something his abuser would also have to apply for before the Education Department would release the information.

"But what hasn't happened is the answers to the questions and the deeper investigation as to what went wrong and how this was allowed to fester on for all these years," he said.

"They're the important answers that need to be addressed and the only way to have those matters looked at seems to be to take this harder action."

Child safety activist and former Labor state minister Allison Ritchie said it was not the first time she had heard claims about the Department of Education.

"There are quite a number of historical cases involving principals or senior teaching staff that I've been made aware of," she said.

"The allegations [are] around attacks and also that those people [are] able to continue employment within the Education Department."

A spokesperson for the Department of Education said it continued to do significant work in child safety.

The Department also said it cooperated fully with police to assist with enquiries of historical sexual assault matters and had processes in place for the management and investigation of any new allegations that were raised.

Ms Ritchie is calling for the State Government to review the handling of such claims.

"They need to understand what went on and they need to understand why the systems failed, and to give those people the opportunity to speak, be heard, and also have confidence that those systems are put in place," she said.