Giving evidence in the Federal Court on Monday, Liberal National Party MP Sam O'Connor recounted a text exchange he had with Ms Higgins on April 19, 2019.
"Sorry, I'm just over it," she wrote to him.
Sam O'Connor said he remembered "the word rape, that's not something that you forget". (Jono Searle/AAP PHOTOS)
"This super f***ed up thing happened a little while ago and I've just lost the fight."
In a phone conversation soon after those texts, Ms Higgins said she had been raped by a male Liberal staffer, Mr O'Connor told the court.
"She told me that he had taken her back to Parliament House and that he had raped her," he said.
"I absolutely remember the word rape, that's not something that you forget."
Mr O'Connor is giving evidence in a defamation trial brought by the man Ms Higgins accuses of raping her, Bruce Lehrmann.
He is suing Network Ten and journalist Lisa Wilkinson over a February 2021 report on The Project regarding the Higgins rape claim, which he vehemently denies and says destroyed his reputation.
Ms Higgins alleges she was sexually assaulted by Lehrmann in Senator Linda Reynolds' office on March 23, 2019.
In subsequent phone calls, Ms Higgins told Mr O'Connor that she didn't want to report the alleged incident to police fearing it would "define her" personally and professionally.
Being a "real go-getter" who was excited about her parliamentary job before the alleged incident, the Liberal National MP recounted how Ms Higgins' demeanour had changed after the alleged rape.
"She absolutely was different," he told the court.
Network Ten and Lisa Wilkinson (left) are being sued over a report on The Project. (Mick Tsikas/AAP PHOTOS)
Network Ten executive producer Christopher Bendall and editorial consultant Peter Meakin are also scheduled to get in the witness box after Mr O'Connor's evidence.
Fiona Brown, who was Senator Reynolds' acting chief of staff at the time of the alleged rape, could also take the stand on Monday afternoon.
Ms Higgins has accused Ms Brown of trying to silence her regarding the rape allegation which came out at a sensitive time before a federal election the coalition was widely considered as being on track to lose.
Lehrmann stood trial in the ACT Supreme Court charged with raping Ms Higgins, but it was derailed by juror misconduct.
Prosecutors did not seek a second trial, citing concerns for Ms Higgins' mental health.
He has been charged with allegedly raping another woman twice in Toowoomba in October 2021 and remains before Queensland courts.
He has not yet entered a plea but lawyers have indicated he denies that allegation.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
23°C