A senior Catholic education officer has apologised to families and victims sexually abused by a bus driver at an Adelaide special school.

A senior Catholic education officer has apologised to the victims of “shocking and appalling” sexual abuse carried out by a bus driver who worked at an Adelaide special school.

Allan Dooley also said the school principal’s handling of the initial complaints in 1991 was “unacceptable”.

Mr Dooley, former director of Catholic Education in the Archdiocese of Adelaide, was giving evidence on Thursday at the royal commission into institutional responses to child sexual abuse.

It is investigating Adelaide’s St Ann’s Special School and its bus driver and volunteer, Brian Perkins, who sexually abused intellectually disabled boys between 1986 and 1991.

“For the former students and families, I am deeply sorry that the abuse at St Ann’s ever occurred,” Mr Dooley said.

He first heard of the abuse in July 2001, when a parent said she suspected her child had been molested after another parent told her former employee Perkins was a pedophile and police had been involved in the case.

The school had provided no information, nor support, and some parents did not even know there was a possibility their children had been abused, she said.

“I was shocked and distressed by the information,” Mr Dooley said.

He immediately put in place processes involving church officials, parents, police and school staff and helped set up a St Ann’s task force.

In August 2001, he met with Claude Hamam, principal at the relevant time, who said he did a police check before employing Perkins and it revealed nothing criminal.

But in June 2003, Mr Hamam admitted he had not checked up on Perkins, who had three previous child abuse convictions, leading Mr Dooley to recommend that Mr Hamam be dismissed.

At the earlier interview, Mr Hamam told him that Perkins provided private respite support for students’ families, taking groups of boys on weekend camps and other excursions.

While the school had a policy that two members of staff accompanied children on trips, the respite was a private arrangement.

Mr Hamam said he told families it was their decision whether or not they allowed their children to go on trips with Perkins and such a move was not sanctioned by the school.

Mr Hamam also said he had no personal reservations about Perkins right up to the time police visited the school in 1991 saying Perkins had been caught with naked photos of students.

Perkins then disappeared, was not arrested until 1993, skipped bail and was not extradited until 2002 after Archbishop Philip Wilson put pressure on police who knew he was in Queensland.

Mr Dooley said police interviewed 90 families who were divided into three groups of children most likely to have been abused by Perkins, children possibly abused and those who did not have contact with him.

“The abuse which occurred at St Ann’s was shocking and appalling and the immediate handling of it in 1991 was unacceptable,” he said.

Perkins died in prison in 2009 after being jailed for 10 years in 2003 after pleading guilty to sex offences.

The hearing is continuing.