The senator said the emergence of the messages needed to be investigated properly to stop it happening again.

“I expect that there will be a proper investigation because, I mean, why would anyone come forward with allegations of assault if this is the result?” Bragg told ABC Radio.

The Australian Federal Police were investigating the unauthorised leak of court material provided under subpoena, the attorney-general confirmed yesterday.

The leaked text messages suggest then-opposition senator Katy Gallagher knew of Higgins’ rape allegations before they were made public in the media in February 2021.

The coalition says there is a case to be made that the now-finance minister misled a Senate estimates hearing in 2021 about her knowledge of the allegations.

Higgins alleged she was raped by fellow Liberal staffer Bruce Lehrmann inside the Parliament House office of then-minister Linda Reynolds in 2019, a claim he has always denied.

Bragg said the way the debate over the matter was unfolding in the Senate was “very, very ugly”.

“This whole thing has been a tawdry affair and it is hugely regrettable how it’s played out publicly,” he said.

The political fallout from the matter continues to escalate as Linda Reynolds threatens to take defamation action against Environment Minister Tanya Plibersek in relation to a television interview that discussed the alleged rape.

The environment minister confirmed she had received an “interesting letter” on Tuesday.

“As far as I’m concerned, all legal options are on the table,” Plibersek said.

The Australian reported Reynolds issued a defamation concerns notice to Plibersek over an interview that aired on Monday in which the Labor minister was accused of wrongly implying the former Liberal frontbencher covered up the rape allegations.

Higgins and Lehrmann both worked for Reynolds at the time of the alleged incident.

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