The Labor government stands accused of seeking to "politically profit" from Ms Higgins' rape allegations.
The former Liberal staffer reached a compensation agreement with the Commonwealth in December 2022 after she launched legal action against her employers in the previous coalition government.
Ms Higgins alleged she was raped by fellow Liberal staffer Bruce Lehrmann in 2019 inside the office of then-coalition minister Linda Reynolds, who they both worked for.
Mr Lehrmann has always denied Ms Higgins' allegation.
Text messages between Ms Higgins and her partner David Sharaz emerged last week suggesting the pair contemplated strategising her story with Senator Gallagher, when she was in opposition, after the rape allegation was made public.
It's further alleged by the opposition that Senator Gallagher misled parliament in 2021 when she rebuffed claims she was tipped off about the rape allegation before it was made public in media reports.
Deputy Liberal leader Sussan Ley told reporters senior government members needed to clear the air on what they knew and when.
"The release of text messages and audio recordings has brought into question the conduct of some senior Labor ministers, and the prime minister himself, relating to whether they chose to weaponise a rape allegation for political purposes," Ms Ley said.
"The government's credibility is in tatters and so every single claim needs to be validated."
But on Saturday, Senator Gallagher told reporters it was "never true" that she had known about Ms Higgins' allegations for weeks and that Labor had "made a decision to weaponise it" as asserted by Minister Reynolds.
"I explained that to Senator Reynolds that night," she said.
"She accepted that explanation and that was some two years ago."
Senator Gallagher admitted she was aware of some allegations in the days leading up to Ms Higgins making them public and that Mr Sharaz had provided her with information.
"I did nothing with that information and I was clear about that at the time," she said.
"So there's absolutely no issue here at all.
"I've been clear, I've been honest and at all times I've been guided by the bravery and courage of a young woman who chose to speak up about her workplace.
"From that, we have had massive changes to that workplace," Senator Gallagher said.
Prime Minister Anthony Albanese on Friday described the opposition attack as "bizarre".
"You had allegations by a Liberal staffer that another Liberal staffer had a sexual assault in a Liberal minister's office, and somehow, somehow Katy Gallagher has some responsibility for what was going on here," he said.
Foreign Minister Penny Wong, meanwhile, has urged people commenting on the Higgins case to consider the impact on the young woman after a retrial of her rape allegations was ruled out due to the effects on her mental health and a potential "risk to life".
Speaking in Perth on Saturday, Ms Wong said those who have published Ms Higgins' private text messages without her consent should "reflect on their responsibilities".
The minister said she wanted to make clear she did not know the details of the allegations before the story became public and she had never made any details of the case public.
"There are others who did know a lot of detail, including Morrison government ministers and they have still failed to account for what they did with that information."
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