Parliament's presiding officers will investigate a physical clash between United Australia Party senator Brian Burston and a senior One Nation staffer.
Senate president Scott Ryan has launched an urgent investigation into an ugly fight between United Australia Party senator Brian Burston and Pauline Hanson's chief of staff.
Senator Ryan has spoken to House of Representatives Speaker Tony Smith about the physical clash between Senator Burston and James Ashby outside a dinner at Parliament House on Wednesday.
"We will be looking into this matter as a matter of urgency. We both regard this as a grave matter," Senator Ryan told parliament on Thursday.
The Senate president said if he didn't report back to parliament on Thursday for legal reasons, he would aim to address an estimates hearing on Monday.
"At this stage I have received no formal information on it but we will be chasing this up in the course of this morning and I plan to speak to senators involved," Senator Ryan said.
He said a range of issues were raised by the incident including the use of media, assault claims and potential privileges concerns around senators being prevented from going about their business.
Mr Ashby filmed Senator Burston in the lead-up to the altercation, which left the One Nation defector with a bandaged hand when he arrived at work on Thursday.
Images appear to show Senator Hanson's office door smeared with streaks of blood.
The stoush erupted after Senator Hanson on Tuesday night used parliamentary privilege to accuse an unnamed senator of sexually harassing at least six staff.
Senator Burston outed himself as the mystery alleged culprit, telling News Corp it was "bullshit", going on to claim he left One Nation after being sexually harassed by Senator Hanson.
The One Nation leader has laughed off the allegations, saying she's "not that desperate".