Greens Senator Lidia Thorpe is facing an internal investigation and the prospect of parliamentary censure, following revelations she failed to disclose a relationship with a former bikie boss.
The ABC revealed on Thursday that Senator Thorpe "briefly dated" the ex-president of the Victorian Rebels outlaw motorcycle gang, Dean Martin, while sitting on a parliamentary law enforcement committee which received confidential police briefings about organised crime.
The revelations have prompted concerns across the political spectrum about a perceived conflict with her role on a law enforcement committee of parliament.
The chair of that committee, Labor Senator Helen Polley, has launched an investigation in to any potential conflicts of interest, instructing the secretariat to examine the minutes of previous meetings.
She said it was necessary as the committee dealt with highly classified and sensitive national security information.
"We need to have that scrutiny to ensure the integrity of the committee," she told the ABC's Afternoon Briefing program.
"There was a demonstration of very poor judgement on behalf of the Greens senator, and this is in fact a very serious matter."
She said the committee would be briefed on the findings of the investigation when it met next week, before determining if any further action needed to be taken.
Prime Minister Anthony Albanese said the investigation was "appropriate".
"My understanding is that the committee of which Senator Thorpe was a member is examining what details went before the committee, to make sure that there has been no conflict there," he said on Friday.
"That's appropriate that that action takes place."
Senator Thorpe has insisted committee documents were "treated in confidence" and the ABC does not suggest she shared confidential information with anyone unauthorised to receive it, nor does the ABC suggest Mr Martin has any continuing association with outlaw motorcycle gangs.
Opposition says it will move a censure motion against Senator Thorpe
But prominent Indigenous leader Marcia Langton said that did not go far enough, and has also called on Mr Bandt to dump Senator Thorpe as the party's Indigenous affairs spokeswoman.
"This is, I would have thought, extremely embarrassing for him as the leader of the Greens party, it must be embarrassing to all the members of the joint parliamentary committee on law enforcement," Professor Langton told the ABC's Afternoon Briefing program.
"I think the portfolio should be taken away from her because of her significant lack of judgement."
Deputy Liberal leader Sussan Ley said the Opposition would also seek to move a censure motion when Parliament resumes next week.
"There is no doubt at all that Lidia Thorpe is unfit to remain in the Australian Senate," Ms Ley said.
Censure motions allow MPs to express their disapproval of their colleagues but don't have any direct legal consequences.
Ms Ley called on the government to support any censure motion next week, with Mr Albanese saying he would consider any proposals put before him.
