The former NSW DPP has defended his office’s advice not to re-charge swim coach Scott Volkers over alleged indecent assaults of three girls.

Former NSW director of public prosecutions Nicholas Cowdery says his office should not have described sex assault allegations against swimming coach Scott Volkers as trivial.

Mr Cowdery last week told the Royal Commission into Institutional Responses to Child Sexual Abuse that he accepted advice in 2004 from the DPP’s senior prosecutor Margaret Cunneen that Mr Volkers should not be re-charged.

In her advice, Ms Cunneen described the alleged abuse as “trivial”.

“I would not have used trivial to describe them,” Mr Cowdery told the commission on Monday.

He later described the alleged indecent assaults against three girls on a scale of criminality.

“In the scale of offending for this kind of offence, they were at – what’s the word I want – at the lesser end of criminality.”

Mr Volkers was a coach with the Australian national swimming team and head of swimming at Queensland’s Academy of Sport until 2002, when he was charged with indecent treatment of three girls in the 1980s.

Queensland prosecutors dropped the case in late 2002.

But after public outcry and an investigation by Queensland’s Crime and Misconduct Commission, Queensland DPP Leanne Clare sought the advice from the NSW DPP on whether Mr Volkers could be re-charged.

Ms Cunneen’s advice included reference to the allegations of one alleged victim as trivial, relative to other sexual assaults.

One of Mr Volkers’ alleged victims, Julie Gilbert, last week criticised Ms Cunneen’s advice – in particular on the grounds there were factors likely to affect the credibility of Mr Volkers’ accusers.

Mr Cowdery was also asked by commission chairman Peter McClellen if the decision not to prosecute could have caused people to doubt the strength of the prosecution system.

“Yes, and it’s had that effect with some individuals in this case,” Mr Cowdery said.

“Do you think it was right, therefore, to express the views that were expressed here in relation to all of the matters?” Justice McClellen asked.

“I think it’s probably too broadly expressed,” Mr Cowdery said.

The hearings continue.