But now Simon Monteiro says that, years before he cut a swath through Sydney's high-society women, it was he who was the victim of violence and sexual abuse at the hands of the Catholic Church's St John of God order.

The 45-year-old, who once dated Oscar nominee Barbara Hershey, is suing the order, three of its brothers, the Maitland diocese, and the Sydney archdiocese in the Supreme Court for at least $750,000 in damages over what he claims was years of rape, intimidation and abuse.

In a statement of claim lodged with the court this year Monteiro says he was ''intimidated, terrified and terrorised'' during his two-year stay at the order's Kendall Grange college for boys with behavioural problems between 1980 and 1982, when he was just 13. Monteiro says that Brother Bernard Kevin McGrath and two other brothers referred to in court documents as ''Brother Joseph'' and ''Brother Daniel'' anally raped him on ''numerous occasions'' while he was at the school.

He claims that during these assaults the three brothers would verbally abuse and belittle him by laughing at him and saying they would kill him if he told anyone of their conduct.

The court documents also allege that more than once, Monteiro witnessed Brother Daniel sexually assault his young, mentally disabled room mate ''George''.

''The second defendant fondled George … as George rocked back and forth in a repetitive manner, which I observed him to do when he was anxious,'' the statement says.

''George would push the second defendant's hand away and the second defendant would hit George in the face until he submitted … ''

Monteiro claims that McGrath and Brother Daniel told him he would be committed to Morisset Mental Asylum if he refused their sexual advances.

Monteiro claims he was ''gravely mentally and physically impaired'' as a result of the abuse he suffered, sustaining post-traumatic stress disorder, bipolar 1 disorder and borderline personality disorder.

He says he has also been unable to maintain ''meaningful heterosexual relationships'' because of his ''inability to deal with conflict'' and ''feelings of shame, terror and dirtiness''.

In its defence submissions filed in the Supreme Court, the St John of God order accepts that Monteiro was a student at Kendall Grange in the early '80s, but denies that it operated and managed the facility. The order denies every allegation of abuse and mistreatment made by Monteiro and says that the action against it is not permissible under the law. It and the Catholic archdiocese of Sydney declined to comment when contacted by Fairfax.

However, if proven, the claims may provide some insight into the psychology behind Monteiro's crimes. In April 2009 he was sentenced to at least seven years and nine months' jail for the aggravated sexual assault of his former girlfriend ''JR'' and the malicious damage and theft of her property.

JR, a professional in her mid-30s, discovered Monteiro's abusive tendencies and dark past, and ended the relationship, ordering him to move out of her eastern suburbs apartment. She returned after a short Christmas holiday to find Monteiro still there and refusing to leave. He then beat and raped her, continuing the torment the next day with a stream of verbal abuse as she tried to get away. When JR later returned to the apartment with police, it had been trashed with paint and cleaning chemicals.

Monteiro was arrested soon after on his way to visit an old friend - Gordon Wood, the man convicted but now acquitted of murdering Sydney model Carolyn Byrne.

This rape and assault was part of a history of mistreating women by Monteiro that dates back to 2000 when he became involved in a plot to discredit an Australian model who alleged she had been raped at a celebrity party in Melbourne. Monteiro was found guilty of intimidating a witness by filming himself having sex with her and then threatening to publish the video online if she didn't withdraw her allegations, but the conviction was overturned on appeal.

In 2004 he surfaced again after being given a suspended jail sentence for stalking a former girlfriend.

Then in 2005, Monteiro was the subject of an apprehended violence order taken out by real estate agent Jaime Upton after an incident at her home.

Just eight months ago Sydney art gallery manager Kay Schubach released a book claiming that she, too, had been abused by Monteiro, describing him as a ''violent narcissist'' who raped and assaulted her.

Monteiro has stopped short of blaming the abuse he allegedly suffered at Kendall Grange for his attacks on women, but several times he has referred to this trauma when facing sentencing.

After treating Monteiro for more than a year, psychologist Dr Gordon Davies found it was almost certain his bipolar disorder was part of the reason for his crimes.

But care workers and counsellors painted a different picture, describing him as have a ''narcissistic personality type'' and as ''belligerent, agitated, self-entitled, abusive'', as well as demanding, and failing to accept responsibility for his actions.

Monteiro is one of hundreds of former Kendall Grange pupils in Australia and New Zealand who say they were abused by St John of God brothers.

McGrath was extradited from Australia and convicted over assaults on boys in the 1960s at the order's New Zealand home.

Court documents show that Monteiro's lawsuit was before the Supreme Court on November 2, with all parties ordered to tender their medical evidence and to undertake informal settlement talks before going back to court in May next year.