Jennifer Herrick at 22, a couple of months after the first assault, with her parents. Credit:Nick McKenzie While the case falls outside the royal commission on child sex abuse because she was 22 when the sexual relationship began, her lawyer, Peter Karp, said: "The adult victims [of clergy abuse] are voiceless victims." Psychologists say such relationships may be compared with those in which doctors have sex with vulnerable patients, while a professor of theology at the Australian Catholic University, Neil Ormerod, believes there may be hundreds of similar cases yet to emerge. Ms Herrick was a shy 19-year-old with bilateral congenital hip dysplasia - a condition causing her to walk with a highly abnormal gait - when her family's priest, Father Knowles, cultivated a relationship with her at his church, Our Lady of Dolours, in Chatswood. Ms Herrick's later psychological reports say she was being groomed. When Ms Herrick turned 22, Father Knowles, who was then 30, unexpectedly initiated intercourse with her, an act she describes as unpleasant and painful but one she felt powerless to stop because of his position. It was the first time Ms Herrick had had sex.

For the next 14 years, Father Knowles maintained a secret sexual relationship with Ms Herrick. "I now understand that my very severe vulnerability allowed him to exploit me by abusing his priestly powerful position for nearly two decades for his sexual needs,'' she said. In 2011, after she lodged a formal complaint, a confidential church investigation found his conduct to be highly inappropriate. Ms Herrick allowed Father Knowles - who as a Catholic priest is meant to be celibate - to have sex with her during a 14-year period and told no one about it. The sex was often hurried, aggressive and sometimes painful. She withdrew from friends and family and grew increasingly anxious, ultimately having a breakdown and losing her promising career as a high school teacher.

"You feel you can't say anything to anybody because he was a priest. When a young, disabled woman is caught up with a priest, you are trapped,'' she said. "I was denied an opportunity to develop normally as a young adult. I could never test out other relationships or have a family. It was a personal and pastoral betrayal." In a report, Ms Herrick's psychologist, Ana Grant, said the priest's conduct had caused Ms Herrick serious post traumatic stress disorder and fell "within the criteria for clergy perpetrated sexual abuse". In September 2011, Father Knowles's superior, Father Graeme Duro, wrote to Ms Herrick acknowledging that she had "endured a great deal of emotional and psychological pain and suffering and that Fr Knowles's inappropriate conduct was to your detriment". But last month, a senior NSW church official, Michael Salmon, advised Ms Herrick's lawyer in writing that Father Knowles had "committed to a prolonged, regular and very intensive and personally confronting programme of therapy" and he would "return to full community life, and to public ministry".

Ms Herrick described the decision as "extremely distressing". Father Knowles was photographed preaching to parishioners last week at St Francis', which hosts 10,000 parishioners a week. In his career with the church, Father Knowles has been appointed as the head of an order and held other senior roles in NSW and Victoria. Mr Karp has acted for many clergy sexual abuse victims. "Vulnerable people in Jennifer's position give their trust to a priest on the understanding that this trust will be returned," he said. "In this instance, the victim is so aggrieved, you would think that justice would demand that he be stood down permanently." Father Duro said last week: ''We express our deep regret at the hurt suffered by the complainant and the harm Fr Knowles's behaviour has caused his fellow religious and the church; we believe everything … to alleviate the complainant's suffering and to address Fr Knowles's responsibility for his actions has been done and it is appropriate for him to return to public ministry.''

Professor Ormerod, who has supported Ms Herrick, said that in reinstating Father Knowles the church sent a "signal to the victim that her situation wasn't serious" when in fact the abuse of trust by the priest had been extensive. Loading Professor Ormerod said he suspected the number of adults abused or in inappropriate relationships with their priests might be greater than the child abuse scandal. A victims' advocate, Chris McIsaac of Broken Rights, said: ''A psychiatrist who targeted a patient sexually could face deregistration, so why not a clergyman?''