The inquiry into disability organisations was told the 10-year-old attended a respite care facility operated by a large provider, FSG Australia.

The child's mother, given the pseudonym CIK, gave evidence that her daughter imitated oral sex when she came home from the facility on the Gold Coast in 2000.

"She lay back on the bed, raised her genitals, craned her head forward and stuck out her tongue," the mother told the Royal Commission into Institutional Responses to Child Sexual Abuse.

"She had never exhibited anything close to this behaviour before. As a parent I had no doubt as to what my daughter was trying to tell me. I believe someone had introduced her to unwelcome oral sex."

CIK told the inquiry her daughter's teacher had observed the child, who has difficulty communicating verbally, displaying similar sexualised behaviour at school.

The commission heard CIK reported her concerns to FSG Australia but was brushed off by its chief executive Vicki Batten.

"It seemed to me like Vicki was trying to deflect responsibility, saying things like, 'She might have seen it on television'," CIK said.

"From what Vicki was saying I believe that she had not considered it possible that my daughter had been sexually abused by an FSG staff member.

"I can only describe the meeting as jaw droppingly awful, intense and not what I expected."

Ms Batten is due to appear before the hearing.

CIK told the commission she did not believe FSG or the Queensland Police made adequate efforts to investigate the allegation.

The commission has heard evidence from another mother, Maree Welch, that FSG failed to adequately address an allegation her daughter Bobbie​, then 12, was raped by an employee in 1995. The alleged perpetrator, John O'Connor​, has consistently denied the claim.

Evidence before the commission is that Mr O'Connor continued to work for FSG for five years after then manager Dorothy Williams became aware of the allegation.

Mrs Williams denied before the commission that FSG was trying to protect its reputation and funding by failing to act appropriately on the initial complaint.

Former FSG coordinator Melissa Edwards told the inquiry the group "did its best to respond" but agreed by today's standards the response was poor.

Former FSG president Lloyd Hastings gave evidence that he did not learn of the allegation until 1998 and was shocked because Mr O'Connor had cared for his son, who has an intellectual disability.

Better regulation and oversight of disability organisations is necessary, the commission heard.

"One of my biggest concerns is that I won't live forever and large organisations like FSG will be running the homes that my daughter will be placed in when I die," CIK said.

The inquiry will examine what safeguards will exist under the National Disability Insurance Scheme which started rolling out nationally this month.

The hearing before Justice Jennifer Coate​ continues.

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