The identities of four people, who are all related, charged over the sexual and physical abuse of three young boys at a performing arts school in regional NSW have been revealed.

The names of Therese Ann Cook, 58, Yyani Cook Williams, 29, Paul Cook, 52, and Clarissa Meredith, 23, had been protected until a suppression order was lifted this afternoon.

They are four of seven people charged by police over the abuse, which is alleged to have occurred between 2014 and 2016 at the school, and at a nearby house.

At the time of the alleged abuse, one of the boys was aged seven and another turned four during that period.

Court documents filed on Thursday also revealed the youngest boy was an infant at the time of the alleged abuse, aged no older than two.

Police have accused Therese Ann Cook of raping a four-year-old boy. ( Supplied )

Therese and Paul Cook are siblings. Yyani Cook Williams is Therese's biological daughter, while Clarissa Meredith is an adopted daughter.

The other three accused are a 20-year-old woman, an 18-year-old man, and a 17-year-old girl, who cannot be named for legal reasons.

All seven are linked to the performing arts school in regional NSW and intend to plead not guilty.

Earlier this week, the group's lawyer Bryan Wrench told a court there was "another side" to this story.

Police allege 4yo was raped on Anzac Day

Charge sheets obtained from the court detail the alleged sexual abuse, including rapes on Anzac Day in 2016.

Police will allege that day, Therese Cook and Yyani Cook Williams raped two of the boys, who were aged four and seven at the time.

The tattered exterior of the performing arts school in regional NSW. ( ABC News: Kathleen Calderwood )

Police also accuse Yyani Cook Williams of forcing the two boys to have sex with each other that same day.

The third alleged victim would have been no older than two at the time he was abused.

There are a total of 127 allegations against the group, including one in which police claim blood was taken from the young boys, who were then forced to drink it.

Police say Paul Cook witnessed the alleged sexual assaults. ( Supplied )

The court documents detailed several other occasions where the accused would allegedly have sex with the boys in the company of one or more of the others.

Therese Cook's charges include deprivation of liberty, detaining for gratification and intimidation.

Yyani Cook Williams is facing eight charges while Clarissa Meredith is facing 13 charges.

Paul Cook is not accused of sexually abusing the boys, but is alleged to have witnessed three sexual assaults and has two charges in relation to filming them.