Francis William Cable, also known as Brother Romuald. (AAP)

Francis William Cable, also known as Brother Romuald. (AAP)

After 13-year-old Andrew Nash took his own life, a now-notorious pedophile Marist brother turned up to his house and asked his mother whether the boy had left a note.

More than four decades later, the Newcastle boy's 90-year-old mother believes the brother had been sexually abusing her son, a royal commission has heard.

Audrey Nash on Tuesday recalled pulling over a taxi driver and telling him to get an ambulance and a priest after finding her son hanging in his bedroom in October, 1974.

Three priests and three Marist brothers, including Andrew's class master Brother Romuald, turned up, she said.

Brother Romuald, whose real name is Francis Cable, asked whether Andrew had left a note or said anything.

"I said 'no'," Ms Nash told the Royal Commission into Institutional Responses to Child Sexual Abuse on Tuesday.

"Then they got in a little huddle.... and had a little chat, and then they left."

Both Ms Nash and one of her other sons, known as CQT, testified they believe the brothers came to their house to make sure no damning evidence was left after Andrew's death.

Ms Nash says she can remember Andrew being out of sorts when he came home late one evening around six months before his death.

He said he'd been to Bar Beach, where it was later revealed Brother Romuald had abused other boys.

"I have been left feeling empty," said Ms Nash, who added she gave her whole life to the Church.

"I also feel so stupid that I used to fear and revere these people."

Ms Nash said she was never visited by the brothers after Andrew's funeral.

She said she went to speak to another priest about her suspicions of abuse in 2012.

"Look Aud, it's been going on forever," she recalled him saying.

"The Romans had their little boys, the Greeks had their little boys and the English aristocrats had their little boys."

The royal commission has heard children were raped and groped at Andrew's and CQT's high school, Marist Brothers at Hamilton.

CQT said many of the teachers could be described as "sadistic thugs" and that one brother kicked a kitten that walked on the school grounds so hard that its "guts" came out

He said numerous suicides by students over the years had affected the community.

"It feels like wave after wave of the kids dying from the 1970s until now," he said.

The royal commission public hearing is examining how Maitland-Newcastle Catholic authorities dealt with allegations of abuse by Brother Romuald as well as men known as Brother Patrick and Brother Dominic.

It was presented with a list of 154 Marist brothers proved or accused of sexual abuse relating to the period from 1980 to 2015.

The hearing is expected to continue on Wednesday.

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© AAP 2016