Coalition senator Michaelia Cash did not know about Brittany Higgins' rape accusations until two years after it allegedly occurred, a jury has heard.
Senator Cash has given evidence in the ACT Supreme Court trial of Bruce Lehrmann.
Lehrmann has pleaded not guilty to sexual intercourse without consent.
Ms Higgins worked for Senator Cash when she was employment and skills minister following the 2019 federal election.
The court has previously heard Ms Higgins talked to Senator Cash about the alleged assault several times during her employment.
But appearing via video link on Monday, Senator Cash said although she was told there had been a security breach in a ministerial office, she was not told about the alleged sexual assault.
She said Ms Higgins had disclosed she and Lehrmann had entered then defence industry minister Linda Reynolds' office - for whom they both worked - after a night out drinking.
She said Ms Higgins had told her she had fallen asleep in the office.
Senator Cash said she did not recall talking to Senator Reynolds about the breach.
Asked by prosecutor Shane Drumgold if an alleged assault between ministerial staffers would be "politically embarrassing", Senator Cash said "absolutely not".
She said she did not understand the political connection, but an assault allegation would need to be addressed.
When Lehrmann's defence lawyer Steven Whybrow suggested it would be "political suicide" for a government to try and cover up a sexual assault allegation, Senator Cash agreed.
"Hence my confusion with the previous line of questioning," she said.
Ms Higgins has previously told the court she felt pressured not to pursue a police complaint because of the potential implications for the Liberal Party at the federal election.
But Senator Cash said when she learned about the alleged assault in 2021 she told Ms Higgins she would be supported "every step of the way".
The court is expecting to hear evidence from Senator Reynolds on Tuesday.
During the second week of the trial, more than 20 witnesses spoke before Ms Higgins returned to complete her cross-examination.
Closing arguments for the case are expected to begin this week after the list of witnesses was cut from nearly 60 to 32.
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