Children whose parents sought a utopian life at an ashram became subject to physical abuse and depraved sexual practices by a yoga master and his partner.

On the second day of a royal commission hearing into an ashram at Mangrove Mountain on the NSW central coast a woman has told how she was forced from the age of 15 to have sex with the spiritual leader Swami Akhandananda when she lived there in the 80s.

The woman was 10 or 11 in 1978 when she and her parents went to live at the ashram. Her parents were sent away to set up other yoga centres and the swami and his partner Shishy became the carers of about 18 children.

The witness, referred to as APL at the commission, said facilities at the Mangrove Mountain ashram were very basic, with children often going hungry. She later discovered that the swami and Shishy had a hot tub, a television and drank alcohol.

“I was told a lot that my parents were inadequate and unnecessary to my life as a swami,” she told the commission.

She said at first Shishy was caring and indulgent but when Akhandananda began sexually abusing her she changed.

“The ashram was supposed to be a celibate community ... if Akhandananda found out that any of the swamis were having sex with each other he would publicly shame and sometimes beat them”.

APL said she and the children were sent out on patrols to find people having sex. They referred to them as “fuck patrols”.

When APL was 15 the swami would make her massage him and force her to have sex and give him oral sex. When she was in pain during his first assault APL said he told her it was dormant (kundalini) energy rising.

She and witnesses who gave evidence on Tuesday said Shishy stayed in the room when she was being abused. APL described her treatment as horrific and said it left her traumatised. She ran away for two days and tried to kill herself but was not even missed.

“In the scheme of things I was just ... a slave to be exploited and I was of no other value whatsoever to the ashram,” she said.

APL gave evidence in 1989 when Akhandananda was convicted of molesting four girls at the ashram. His conviction was overturned by the high court in 1991 and he died in 1998 in Cairns.

Shishy, who met Akhandananda when she was 16, fled the ashram in 1985 and gave evidence at his trial.

She will give evidence to the royal commission into institutional responses to child sexual abuse probably next week.