Finance Minister Katy Gallagher has described media reports making use of Brittany Higgins’ leaked text messages as the “most egregious abuse of privacy I’ve ever seen”.

Senator Gallagher challenged Coalition frontbenchers to reconcile  inconsistencies in their own accounts of how they responded to a scandal that shook Australian politics to its foundation two years ago with the airing of a television interview.

Ms Higgins alleged she was raped by a fellow Liberal staffer, but a trial collapsed due to juror misconduct and the case was dropped due to concerns about the ongoing impact on her mental health.

Opposition Leader Peter Dutton rallied MPs in the Coalition party room for a continued attack on Senator Gallagher for saying she had no prior knowledge of the case before it became public.

“A group of Labor operatives conspired to maximise the damage – and it was absolutely brazen,” he told MPs.

Senator Gallagher’s June 2021 claim that “no one had any knowledge” of Ms Higgins’ allegations has been, Coalition MPs say, contradicted by newspaper reports based on a leak of her private text messages.

News Corporation journalist Sharri Markson reported on Monday that text messages showed David Sharaz, Ms Higgins’ boyfriend, had met Senator Gallagher one week before the interview aired, when she was told of the upcoming broadcast.

(Markson recently broke a scoop based on a leak of former NSW premier Dominic Perrottet’s wife’s medical records).

In the upper house on Tuesday, Senator Gallagher said her comments in the Senate two years ago were about the broader question of “whether I was involved in that matter becoming public”.

“And I was not,” she said.

She did not deny being informed that Ms Higgins was preparing to go public, but said she kept the confidence and did nothing to act on the information.

She also said that Linda Reynolds, Ms Higgins’ former boss, whom she had made the comments in response to, during the 2021 back-and-forth, had accepted this version of events during a private conversation later on the same evening.

“It does seem strange to me I’m providing a statement to the Senate, but those that were much closer to the events in 2019 have not done so,” she said.

“At the heart of this whole story sits the wellbeing, or otherwise, of a young woman who came forward and made allegations on her own terms.”

• Liberal senator urges inquiry into Higgins leaks

Senator claims she was defamed

Meanwhile, Liberal Senator Linda Reynolds has taken legal action against Environment Minister Tanya Plibersek, claiming Ms Plibersek defamed her in a television interview broadcast on Monday by stating she had “covered up” Brittany Higgins’ alleged rape.

The Australian reported Senator Reynolds accused Ms Plibersek of making false statements throughout the Channel 7 Sunrise interview, that implied she had acted inappropriately during the investigation of Ms Higgins’ allegations and had attempted to “hide the commission of a criminal offence”.

Ms Plibersek stated in the interview: “The central point here is that a young woman made an allegation that she had been sexually assaulted in her workplace and that it had been inappropriately investigated, even covered up by her employers.”

Senator Reynolds confirmed on Tuesday that her lawyers had sent a concerns notice that accused Ms Plibersek of making false statements in the interview.

Attorney-General weighs in

Mr Dutton previously denied knowing about the alleged rape in the defence minister’s office in 2019.

The Australian Federal Police informed his office, as the former minister responsible for the force, then but he says he did not personally become aware until the same time as Senator Gallagher, 18 months later.

There have been several reported leaks of Ms Higgins’ personal information in coverage of the case, including the pages of her diary.

On Tuesday Attorney-General Mark Dreyfus told question time he understood the Australian Federal Police (AFP) had received a complaint about the leaks which, he said, could amount to a breach of rules and contempt of court.

“I am deeply concerned about the apparent unauthorised publication of material produced as a result of a subpoena in the criminal trial of Mr Bruce Lehrmann,” Mr Dreyfus said.

Former prime minister Scott Morrison also clarified his own account of his role in responding to the scandal.

Mr Morrison made a rare statement to Parliament on Tuesday, two years after he gave a speech claiming to have discussed Ms Higgins’ case with her former boss and the office chief of staff, Fiona Brown.

Ms Brown told a newspaper on the weekend that he had not, and had therefore misled the House of Representatives.

“While I believe my response to [be] accurate at the time, I cannot obviously fully discount her recollection of those events now were the more accurate,” Mr Morrison told Parliament.