Mum told reporting abuse is too traumatic

A mother has cried as she told how her three children, two of them disabled, were put through a "horrendous" three-year legal ordeal when the family reported a carer had indecently assaulted her six-year old son.

The woman using the pseudonym CDB reported the assault on her youngest son, who is not disabled, by a carer which the family had been sent in 2011 by a respite care agency in the ACT.

Two of her sons, who were aged seven and 11 at the time, are disabled and have communication difficulties.

CDB and her husband went to police when CDE, their six-year-old, told them he was sore because the carer had been touching his penis.

Her disabled sons who were in the house when the abuse happened were called as witnesses.

A woman from the rape crisis centre was appointed to support her 11-year-old disabled son.

CDB said the woman warned the family not to expect anything from the process.

"'If you are lucky, you will get out of this reasonably unscathed but you know people have ended up with post-traumatic stress disorder'," CDB said she was told.

Police decided it was too difficult to get evidence from her second disabled son and options such as using a speech therapist were never explored.

After a number of pre-trial hearings and a mistrial, the case was finally heard in February 2014.

CDB said during the cross-examination the defence lawyer implied she and her husband were setting up some kind of lie.

"He also destroyed us as a family by putting blame on our parenting and our children's disabilities."

The jury returned a not guilty verdict.

"We lost our faith in the justice system," she said.

Australian Federal Police Detective Sergeant David Crowe told the commission three other complaints had been made to police about that carer at the time, one involving an allegation he had sex with a person with Down Syndrome.

Sgt Crowe who is with the AFP's Sexual Assault and Child Abuse team was not directly involved in the investigation, but told the commission records showed there was no prosecution because there was "insufficient evidence".