WARNING: Graphic and confronting content.

An old friend of the Adelaide woman who accused Christian Porter of rape has revealed the reason why she believed her and what she registered as “sinister” elements of her allegations.

In new documents released by the Federal Court on Thursday, a transcript of Jo Dyer’s previously unpublished interview with ABC journalist Louise Milligan has detailed when she discovered that her old school friend alleged she had been anally raped by Mr Porter as a teenager.

Mr Porter denies the allegation and is suing the ABC for defamation who reported a cabinet minister was accused of a 1988 rape, although it did not mention his name. He has since discontinued the case.

The documents released by the Federal Court also include the “dossier” including the accuser’s account of the allegations in her own words.

His accuser died by suicide on June 24, 2020, with friends and supporters marking the one-year anniversary of her death on Thursday by lighting “candles for Kate”.

In a transcript released by the Federal Court, Milligan asks Ms Dyer, “What made you think that K was telling the truth?”

“There are a number of reasons why I thought K was telling the truth,’’ she said.

“First and foremost was the story that she told was so clear and so consistent and so detailed. I believed the story. Secondly, really, the incident as she described it was not … the acts that she described were not something that a 16-year-old virgin would consent to.”

Due to the nature of the alleged events described, Ms Dyer said she found it hard to believe it could have been consensual.

Mr Porter denies having sex with the teenager and has previously stated: “Nothing in the allegations that have been printed ever happened.”

When recounting her version of events, the woman states the encounter started off as consensual.

She claims Mr Porter asked her for a “pearl necklace”, which she agreed to despite not knowing what it was.

She then alleges he forced her to have oral sex.

After she vomited on her dress, she alleged he took her to a bathroom and washed her. When she woke up later in the evening, she alleged he was anally raping her.

“So there was no ambiguity, it seemed to me, as to whether or not this was a consensual act that got out of hand or anything of that nature,” Ms Dyer told the ABC, according to the transcript released by the court.

“It seemed to me that it was an aggressive and violent act, that no 16-year-old having her first sexual encounter would sign up for.

“Thirdly, there was a level of sinister detail in it which seemed to me that once the act had occurred and K had resisted that there was strategic thinking around it by C to cover up the evidence. He – K told me – that while she was practically hysterical, and gave her a bath.

“They were staying at the Women’s College at the University of Sydney. They were shared bathrooms. Why on earth would you do something like that? After a so-called consensual sexual encounter. You wouldn’t go traipsing down the hallway to a shared bathroom in the middle of the night or early in the morning?”

In the accuser’s unsigned affidavit however, she is unclear whether he took her to a bath or a shower.

Ms Dyer told the ABC that Mr Porter and his accuser had been out drinking, partying, until very late one night as teenagers after a debating conference.

“They were walking back to the university campus, C offered to walk K back to her college. He had been cracking on to her a bit. She wasn’t interested in his advances, she wasn’t in that mood, late at night. But, he walked her back to her room. Came into the room, they started kissing, she was reluctant, but no harm in a kiss.

“At a certain point, she moved away, she resisted. She said she was not interested in pursuing anything further. C was not going to take no for an answer. I think he thought – the way she described it, there was a lot of alcohol involved, I think he thought he could persuade her as they went along.

“There was increasing sexual activity. He was quite repulsive in the language that he used during the encounter. She resisted more strongly because of this. It was very clear, the way she described it, there was no ambiguity as to whether or not she was consenting.

“And at a certain point, he raped her, and he raped her anally. When he finished, she was incredibly distressed, hysterical almost, in tears, on the bed, he was trying to calm her down. At a certain point, he suggested that the best course of action would be for her to take a bath. Throughout that time, he was seeking to comfort her. And the way in which he did this was to stroke her and tell her that it was all going to be OK because this was just a bad dream.

“She was a virgin. She had not had sexual experiences. She was not a sexually experienced person. She never viewed this – in later discussions, she never viewed this as the way she lost her virginity.”

Ms Dyer also states in the transcript when she connected with the woman some years later she was a different person.

“In the world of debating, there were many stars shining in the firmament. But K really shone the brightest, or certainly one of the brightest,’’ she said.

“And she did not achieve everything that the potential that she showed back then would have suggested that she would.

“When we reconnected, K was a very different person. She was consumed with a trauma which she told me, deeply and consistently, was a result of an assault that had occurred, early in 1988, and her life at that point was really devoted to exploring how she could get some kind of justice, accountability and peace from that.

“And I guess finally, her life was derailed.”