A Catholic religious order has apologised after one of their priests masqueraded as a psychologist to abuse a vulnerable young woman.

Father Terence O’Brien, who was a member of the Salesians of Don Bosco, sexually abused the woman, known as Beth, when she was taken to him for counseling after her mother died suddenly.

But the priest, who has since died, told his victim that he was “teaching her how to love” as he abused her for nine years between 1975 and 1984.

Father O’Brien was charged in 1996 with abusing three children but the case never came to court. He was also investigated by Scotland Yard as part of Operation Torva, a probe into the Salesians.

The current head of the order, Reverend Gerry Briody, apologised to Beth for the abuse carried out by Father O’Brien. The order has also settled a civil claim against them with her for sex abuse.

In a letter Rev Briody said Beth had reported that she “had been sexually abused and assaulted by Father Terence O’Brien on a significant number of occasions”.

He added: “The account states that you had gone to him for counselling, were in a vulnerable state and that Fr O’Brien taking advantage of this required you in your subsequent sessions with him to submit to therapy, massage and other practices during which the ‘treatments’ included various forms of serious sexual assault.

“As priests and, and as Salesians of Don Bosco, we are called to respond to the needs of others, and especially young people… I am profoundly saddened to hear that in contrast to this your experience was of shocking sexual abuse at the hands of a Salesian priest. I offer you a heartfelt and unreserved apology for all that you experienced.”

Beth, not her real name, was abused at the Fr O’Brien’s house, which was provided by the order, on the same site as the Saelsian College, a former school in Battersea, South London.

She said: “After my mum died my mental health deteriorated and because of the pressure I was under I was suicidal. I turned to my cousin who was a nun who realised something was seriously wrong and took me to her convent. They knew O’Brien well as he had done lots of work with the sisters.

“He told me I had psychological problems with my sexuality and used this as a pretext to sexually assault me. I had very little sex education so had insufficient knowledge to know he was lying. He took complete advantage of me. I tried to resist him but he told me that demonstrated the problems I had with my sexuality. I was totally confused, especially as I knew how strict the church’s teaching is regarding sex. He convinced me that I must have a problem. I felt very ashamed.

“He told me I mustn’t tell anyone else or it would interfere with the treatment. I thought the nuns knew what his treatment entailed so it must be acceptable. I was miserable because I hated it.”

O’Brien saw Beth once or twice a week from autumn 1975. After she went away to nurse in summer 1976 O’Brien insisted she visit him every two months. In 1984 Beth told O’Brien that she was engaged to be married. The sessions stopped abruptly with no explanation.

“I was left confused and could never figure out why he didn’t want to meet my fiancé,” she said.

Beth said she only came forward when the Jimmy Savile scandal broke in 2012.

She said: “It was only when I saw what Jimmy Savile had been doing to hundreds of people that the truth of what Father O’Brien had done really dawned on me. When I looked into O’Brien’s past I suddenly realised, thanks to the Lantern Trust, what a horrific paedophile he had been. I thought that people needed to know what he did.

“When I was told that O’Brien had absolutely no psychological qualifications it was a massive shock. He had even made me pay £200 for the ‘treatment’. My monthly rent in London was £32 at the time. Others must’ve known he had no psychological qualifications but he was allowed to carry on regardless. I have been suicidal at times. He has destroyed much of my life and I will be haunted by the memories forever.

“I feel completely and utterly betrayed by him and disgusted. I appreciate the apology from the Salesians and that they have acknowledged the truth about his activities, but I am concerned that the prospect of avoiding he spotlight of the Independent Child Abuse Inquiry may be their motivation. I wanted my to tell my story so people realise how vigilant they need to be to ensure children are protected from such terrible evil.”

Richard Scorer, a specialist abuse lawyer from Slater and Gordon, said: “Father O’Brien not only abused his position as a priest but he also masqueraded as a psychologist so he could attack young people. This was a disgusting betrayal of trust that should never have been allowed to happen.

“I am pleased we have managed to get some justice for Beth by settling her civil claims and hope that and the apology will give her the ability to move on with her life.”