A woman has told an inquiry how she was sexually abused by a priest and forced to drink her own urine to stay hydrated at St Joseph's Neerkol Orphanage at Rockhampton.

Diane Carpenter, who lived at Neerkol intermittently until she turned 17, was giving evidence at the Royal Commission into Institutional Responses to Child Sexual Abuse, which is holding public hearings in the central Queensland city.

The inquiry is continuing to hear evidence from former residents of the orphanage, where hundreds of children were physically and sexually abused from the 1940s to 1970s.

Ms Carpenter, one of several Aboriginal children at the orphanage, said her sexual abuse at the hands of Father Michael Hayes, who ministered to the Indigenous children, was witnessed by another priest.

She also gave evidence she also witnessed an orphanage employee sodomising a young boy, an episode that she said made her physically ill.

"The first time I was abused was around four months after my father died," Ms Carpenter said.

"I went to visit Father Hayes at the presbytery opposite the Catholic Church in Rockhampton because, naturally, I was feeling upset and missing my father.

"While I was there Father Hayes penetrated my vagina with his finger.

"Father Davey entered the room and saw what Father Hayes was doing to me.

"[Father Hayes] would frequently touch the Aboriginal girls; for example, I went back to Neerkol when Father Hayes was visiting; he would put his hands up my blouse and fondle my breasts."

Father Hayes died without ever being charged with an offence.

Ms Carpenter said she believed all five of her siblings were sexually abused at the orphanage, where children from the same family were kept apart.

The number of children resident at Neerkol varied from 150 to 500, depending on the year. ( ABC TV News - file image )

Ms Carpenter told the inquiry the Sisters of Mercy nuns who ran the orphanage regularly kicked the children as they slept.

"Beatings were by punishing, shaking or being belted with a stick, or a leather strap. And it was on the bare bottom.

"On one occasion I was locked in an extremely hot room and was forced to drink my own urine to stay hydrated."

Ms Carpenter also recalled a nun ordering another girl to scrub her.

"I was very brown, you know, black and I was scrubbed with a scrubbing brush," Ms Carpenter said.

"I still have scars on my back today because it was really hard and it was like somebody was cutting me with a knife."

Ms Carpenter received about $10,000 compensation from a civil case launched on behalf of Neerkol victims.

'Experiences has eroded my trust in police'

At 13, Ms Carpenter said, she was also sexually abused by the son of a farming family she was billeted with over the holidays.

When she reported the abuse to the state government inspector, she was beaten by the nuns for reporting it.

Ms Carpenter gave evidence on another occasion she told a friendly policeman that she was being sexually abused by Father Hayes, but the policeman put an end to the conversation and she never saw him again.

At 17, she reported her abuse to a policeman in Mackay.

He told her it had nothing to do with the police.

"This experience further eroded my trust in police and authorities. I felt as though no one in a position of power would help or support," she said.

The commission also heard evidence from 54-year-old Joseph Kiernan who described the brutal treatment he suffered at the hands of the sisters, and sexual abuse by priests.

Mr Kiernan said he was sexually abused by Father Reginal Durhum, and that the priest would then make him confess his sins.

He told the inquiry he was bullied by some of the nuns, and the beatings were so brutal they made him go deaf.

"Throughout my life I have had continuing problems with my hearing," Mr Kiernan said.

"I went to see a specialist and he told me that I was clinically classed as being deaf.

"The specialist told me that it was probably the result of being hit around the ears frequently.

"I now have to wear hearing aids."

He also said a groundsman at the orphanage, Kevin Baker, would often go into the bathroom and touch boys while they were showering to "make sure they were clean".

'Things that happened make me feel disgusted'

Another witness, who told the inquiry he suffered from ongoing mental health issues after being abused at Neerkol, also accused Mr Baker of sexually abusing him and other children.

The witness, referred to as AYN, said he had no life skills and suffered from depression and anxiety after being abused by Mr Baker.

He also said he lived alone and could not maintain relationships, and that he did not received adequate compensation.

"The things that happened to me make me feel disgusted," he said.

After several legal proceedings Mr Baker was never convicted of any offence and he denies the allegations.