The chair of the royal commission into institutional child sex abuse has told a hearing in Sydney that he had not previously understood the “devastating and long-lasting effect” of sex abuse.

Justice Peter McClellan AM spoke at the opening of the public hearing in Sydney this morning. He said almost 400 people had so far told their stories to the commissioners, through private hearings, with a further 1178 yet to be assessed for a private session.

Referring to the many inquiries that have previously dealt with child abuse, McClellan said this royal commission was a way of joining together all Australian governments to respond to continuing anxiety in the community about these issues.

“It is well-known that the sexual abuse of children has been widespread in the Australian community. However, the full range of institutions in which it has occurred is not generally understood. Furthermore, the character and effectiveness of the response to allegations by institutions in which it has occurred has not generally been exposed.”

Already, some preliminary themes were emerging, he said. “It is apparent that where an organisation lacks an appropriate culture and there are not appropriate practices and training of staff within the organisation, there is a risk that sexual abuse will occur.

“In my role as a judge I have been called upon to review many of the sentences imposed upon people convicted of the sexual abuse of children but I readily acknowledge that, until I began my work with the commission, I did not adequately appreciate the devastating and long-lasting effect which sexual abuse however inflicted can have on an individual’s life.”

Today’s public hearing is the first of four scheduled for this year. This one will focus on the actions of former Scout leader Steven Larkins, who was also a former general manager of the Hunter Aboriginal Children’s Services in NSW.

“His grandparents had said that before the abuse he was happy and carefree, but afterwards he became a shell of the person he was.”

This morning two men, who were children at the time, are giving evidence about the abuse they suffered at the hands of Larkins in the early- to mid-1990s. Larkins pleaded guilty last year to two counts of aggravated indecent assault, three counts of possessing child abuse material and three counts of dishonesty offences, which concern creating a false ‘working with children’ check clearance and making a false statutory declaration about his contact with children. He is currently in custody.

This morning a statement from one of the witnesses was read from the bar table, detailing the sexual abuse by Larkins at a scout camping trip. He said that he “felt dirty, and thought it was all his fault”. He said he did not discuss it with anyone for months, and was afraid to tell his mother as he thought she would be angry with him. He later told his mother and she took him to the Newcastle police station. He now felt great relief that finally something had been done about Larkins.

He said he now did not trust anyone, except for his wife, and had difficulties with relationships. His grandparents had said that before the abuse he was happy and carefree, but afterwards he became a shell of the person he was.

The commission’s second hearing will look into the YMCA and its former employee Jonathan Lord, followed by the North Coast Children’s Home, operated by the Anglican Diocese of Grafton. The final hearing this year will hear evidence about the Catholic Church’s Towards Healing process, designed to deal with victims of sexual abuse.

McClellan flagged that next year’s hearings will look at an orphanage, as well as one or more institutions within the Catholic Church and the Salvation Army.

Set up by then-prime minister Julia Gillard on November 12 last year, the commission is intended to “inquire into how institutions with a responsibility for children have managed and responded to allegations and instances of child sexual abuse” in educational and religious organisations, as well as sporting groups, state institutions and youth organisations. The commissioners can investigate any private or public organisation involved with children. It is scheduled to bring down an interim report by June 30 next year. The then-Gillard government committed $434 million over four years to fund it, including $43 million for offices and hearing rooms, $20 million a year for financial assistance for witnesses, and $45 million for victim support services.

The commission receives an average of 22 new callers a day, which is expected to increase now that the public hearings have started. It has already conducted private sessions in all capital cities.

Some have estimated the commission could run for up to a decade.

*Additional research by Crikey intern Angelo Risso