Senator Linda Reynolds says she sent confidential documents related to Brittany Higgins to a journalist because she believed the attorney-general was "stitching" her up.
The former minister is suing Ms Higgins for defamation over a series of social media posts containing alleged mistruths that she believes have damaged her reputation.
She told a Perth court on Thursday that she sent three documents to a journalist from The Australian, Janet Albrechtsen, related to Ms Higgins' commonwealth settlement.
"I picked her because she is the most balanced," she said.
"There was no agreement or anything that she would be favourable to me in any way."
Senator Reynolds used her personal Gmail account to sent the letters sent to her by her commonwealth lawyer.
Asked by Ms Higgins' lawyer, Rachael Young, why she did it, the senator said she wanted the reporter to know she had been denied the ability to counter Ms Higgins' claims that she'd mishandled her alleged rape.
"Claims that had expired. The statute of limitations had expired," Senator Reynolds said.
"Yes, I was incredibly angry because I could see the attorney-general of this nation was stitching me up. So absolutely I did want her to know and I wanted the public to know."
The senator denied she chose Albrechtsen because she believed the journalist would be less favourable to Ms Higgins in her reporting than others.
"I provided her with evidence of my claims of corruption and then it was up to her in how she reported it," she said.
"I never saw the final claims against me, the statement of liability and I was not provided any opportunity to defend the claims.
"They didn't allow me to defend myself ... I could have still defended them had I been given the opportunity," she said.
Senator Reynolds denied she used her personal email account to sent the documents to hide her actions from scrutiny.
She agreed with Ms Young that she was pleased when she saw Albrechtsen's article a few days later.
But she denied her motivation for passing on the documents was to raise questions about Ms Higgins' $2.4 million settlement.
"It's the other way around ... It's about the way the Commonwealth dealt with the claim," she said.
"I had no issue with Ms Higgins in this process at all. I was very clear that this was about the attorney-general and how he had, I believe, corruptly manipulated the law to muzzle me so my issue was never with Ms Higgins.
Ms Young also quizzed the senator about the distress Albrechtsen's article could cause Ms Higgins and her ongoing mental health issues.
"I had no indication of what the state of (Ms Higgins') mental health was and what was top of my mind was exposing what I believe to be corruption by the attorney-general,
"And you didn't seek to find out what the state of her mental health conditions was prior to you sending these three communications?" Ms Young said.
"No," the senator replied.
Ms Higgins' defence relies on truth and that it was reasonable to comment on issues of public interest concerning government and political matters.
She alleged colleague Bruce Lehrmann raped her in Senator Reynolds' office in 2019.
Lehrmann has always denied the allegation and his criminal trial was derailed by juror misconduct.
The trial continues.
