Brutal abuse suffered by teenage boys at a former Australian Navy base has "destroyed" the lives of men today, the Royal Commission into Defence and Veteran Suicide has been told.

Retired judge Len Roberts-Smith — the former chair of the Defence Abuse Response Taskforce (DART) — has given evidence at the public inquiry in Townsville.

DART was established in 2012 to assist complainants who had suffered abuse, harassment and bullying in the Australian Defence Force prior to April 2011.

Mr Roberts-Smith said the taskforce received 238 complaints related to the former HMAS Leeuwin base in Western Australia's Fremantle, which operated between the 1960s and the 1980s.

"We were talking about men … in their 60s and 70s, and so on, whose lives had been destroyed by the abuse and, in many instances, if not most, had never told anybody about the abuse they had suffered or the impact in had on their lives," he said.

Mr Roberts-Smith said most of the abuse was inflicted by older recruits onto their junior counterparts, who were as young as 15 years of age.

"We are talking here about serious abuse, like running the gauntlet, bashing, being raped with broom handles and mop handles," he said.

"They also knew that, if they did say anything, they would be brutalised for doing so.

"And they did know that, if they did manage to say something to staff, the staff would either ignore it or would pass [the matter] back to the perpetrator."

In total, DART received more than 2,400 complaints.

Mr Roberts-Smith said it was clear the instances of abuse examined by the taskforce continued to have long-lasting impacts on victims.

"The mental and emotional and psychological consequences literally last a lifetime," he said.

Mr Roberts-Smith also spoke about the limited scope of the taskforce in probing abuse allegations.

"We had no investigative function, no legal determinative function, we couldn't make findings," he said.

"It was a rather challenging environment in which to operate."

The former DART chair said the taskforce faced a number of obstacles, including challenges in obtaining documents from Defence.

"Sometimes units had disposed of, or not kept records [that] ought to have been kept," he said.

Mr Roberts-Smith will continue giving evidence on Wednesday, before the royal commission wraps up its Townsville hearings on Thursday.

https://www.abc.net.au/news/2022-06-28/qld-royal-commission-into-defence-and-veteran-suicide-townsville/101178548