Ben Roberts-Smith's former girlfriend has told a Sydney court she did not report an allegation she had been assaulted by the war veteran to police out of fear he would seek "payback".
Mr Roberts-Smith denies striking the woman and is suing three newspapers for defamation, claiming a series of 2018 reports contained false allegations of domestic violence, bullying and unlawful killings in Afghanistan.
The Federal Court has heard the Victoria Cross recipient had a relationship with the woman, codenamed Person 17, from October 2017 to April 2018 when they were both married.
Person 17 has alleged Mr Roberts-Smith punched her in the face in their Canberra Hotel room after becoming "very angry" her drunken behaviour at a Parliament House function may have exposed the affair.
In subsequent weeks, she said her husband urged her to make a police report.
"I didn't really want to, because I was just afraid that no-one would believe me," Person 17 told the court.
"I blamed myself for what had happened in Canberra, I thought that I got what I deserved for being silly."
Person 17, who disclosed the relationship to Mr Roberts-Smith's then-wife Emma Roberts on April 6 that year, recalled going to a police station but wanting to speak to a senior officer.
"I was worried about Ben's connections in the military and the police," she said.
She was not able to speak to a senior officer and did not proceed because she did not want to say who she had been having an affair with, the court heard.
Person 17 said she changed her mind about speaking to the media in May 2018 because she was afraid of "what I was caught up in, what people really knew about".
She had a meeting with journalist Nick McKenzie, who is a respondent in the case, and was again encouraged to speak to police.
The witness recalled saying to him "I just don't think they're going to take it seriously" and "I don't want to be involved in any sort of trial".
"I was torn between not wanting to do anything, but feeling like I had to do something to protect myself."
At a meeting with Australian Federal Police officers, Person 17 said she did not want to make a formal complaint.
"I said to them ... I'm scared, I'm scared of what he's going to do," she told the court.
"I'm scared if this all becomes public somehow, he'll think it was my doing and he'll seek payback."
Under cross-examination by Mr Roberts-Smith's barrister Bruce McClintock SC, Person 17 agreed she had told Vice Admiral Ray Griggs about the affair at the Parliament House function.
The court heard she fell down some stairs while trying to leave and suffered a bruise to her thigh and soreness on the left side of her forehead.
"Did he (Mr Roberts-Smith) hit you in the same spot where you had sustained the injury when you fell down the stairs?" Mr McClintock asked.
"It was in the same area, but not the same spot," Person 17 replied.
The witness rejected a suggestion that she was so drunk she could not hold herself up without support from walls. She described her recall of the evening as "fairly good".
Person 17 yesterday said Mr Roberts-Smith coached her to explain her black eye as being a result of her fall.
Today she denied the fall resulted in swelling on her head "between the size of half a golf ball and half a tennis ball".
Person 17 agreed that within a week of the Canberra function, she was proposing to meet with Mr Roberts-Smith in a Brisbane hotel, contemplating a night alone with him.
"It is not a good indication of fear, is it, if you want to replicate the very situation where you say the incident had occurred?" Mr McClintock asked.
"I was simultaneously in love with him and afraid of him," she replied.
Mr McClintock put to the witness that she was "an educated woman", "independently wealthy", who took steps to leave her husband and put "considerable effort" into regularly meeting with Mr Roberts-Smith, which she accepted.
"My client had no power over you, did he?" the barrister asked.
"He did," she replied.
Person 17 told the court that three days before she informed Emma Roberts about the affair, she was approached on a beach by a stranger during her morning walk.
She said the man had photographs of what looked like her and Mr Roberts-Smith having sex in a Brisbane hotel, shot from outside the building.
Person 17 told the court the man threatened to make the photographs public if she did not tell Ms Roberts about the relationship.
Under cross-examination, Mr McClintock suggested the story about the photographs was a "straight up barefaced lie", which she denied.
Person 17 said she was "in shock" and didn't ask the person, who she described as "like a sort of bikie type" or "army person", how he obtained the photographs.
"I said 'Who are you?' But he didn't answer," the witness said.
Person 17 denied she had concocted the beach story to give herself an "explanation" for what Mr McClintock called her "tawdry conduct" in visiting Emma Roberts to break up the marriage.
The trial, before Justice Anthony Besanko, continues.
