Adam Bandt's office has confirmed the Greens leader has met with Australian Federal Police to discuss Senator Lidia Thorpe's undisclosed relationship with a former bikie boss.
Senator Thorpe admitted last month that she briefly dated the ex-head of the Rebels outlaw motorcycle gang in Victoria, Dean Martin, while also serving on parliament's law enforcement committee.
She did not disclose that relationship to her party leader, despite warnings from her staff to do so.
Mr Bandt stripped Senator Thorpe of her leadership position in the party and committed to meeting with the AFP over the matter, which his office has confirmed he has since done, though he could not disclose the contents of that briefing.
Senator Thorpe also volunteered herself to be referred to parliament's powerful privileges committee, which looks into potential code of conduct breaches.
The law enforcement committee sent a detailed response to the senate privileges committee about a week ago on its own inquiries.
The ABC has been told the committee noted Senator Thorpe's failure to declare a conflict of interest and detailed the hearings attended by the Victorian senator, including with the AFP and the Australian Criminal Intelligence Commission.
It is understood the committee reported that while there was no inquiry into outlaw motorcycle groups during Senator Thorpe's time as a member, it heard evidence about bikie gang activity during hearings on organised crime.
The Greens' sole member on the senate privileges committee is Tasmanian Nick McKim.
If the privileges committee rules that Senator Thorpe had failed to disclose a conflict of interest, she would likely face senate censure.
One parliamentary insider told the ABC that this would be "new territory" for the privileges committee insofar as it has never had a similar matter raised with it.
Review of Thorpe's office continues following complaint
A cultural review of Senator Thorpe's office by the Finance Department has been underway after a formal complaint was made to the Greens in June this year.
In it, a former staffer to Senator Thorpe complained that they believed there was a breach of workplace health and safety in the senator's office.
The staffer said Senator Thorpe "rarely" attended the office, and that when she was asked to come in she would become "defensive and rude".
"She is often missing and uncontactable, sometimes for days. This makes getting approvals for work incredibly difficult and at times impossible," the staffer said in a complaint seen by the ABC.
"On more than one occasion she has completely disengaged because she is too overwhelmed and advised all staff not to contact her at all, until she advises otherwise.
"Party members and community members have complained ... about her lack of reliability or that in the event she does attend a meeting or event that she was unprepared."
Mr Bandt previously said his office had "expressed regret to [the complainant] about what occurred" and was supporting Senator Thorpe and her staff in the review process.
He said it was a matter for the appropriate authorities to determine whether there was a breach of work health and safety, and his office awaited the outcome of the Department of Finance review.
Senator Thorpe has been contacted for comment.
