A senior Fair Work Commission member is under investigation for letting off fireworks at a boozy Christmas balcony party at the industrial umpire's Sydney offices.
Deputy president Gerard Boyce has been referred to federal workplace safety regulator Comcare and NSW Police over the alleged incident in December.
The commission's acting general manager Murray Furlong faced questions about the explosive allegations at Senate estimates on Wednesday.
He said general manager Bernadette O'Neill had received information firecrackers were let off on a balcony at an unofficial party on December 11.
She was also told some of the firecrackers may have been thrown off the balcony onto the Sydney street.
Mr Boyce's behaviour has been a regular fixture at Senate estimates hearings over the past two years.
He was sanctioned after being forced to remove from his office scantily clad erotic figurines that he painted.
Comcare found his actions were a "psychological hazard" but didn't breach work health and safety laws.
Labor senator Deborah O'Neill said there were reports he set off firecrackers on the balcony of the commission's offices after a "big, boozy Christmas party".
"He retains his position under this government, gets another go and at Christmas decides he's going to have a little party and throw a few crackers," she told parliament.
"The government's done nothing about it."
Mr Furlong said he was unaware if Mr Boyce had been asked to surrender any other fireworks.
Fair Work's Ms O'Neill sought legal advice after becoming concerned fireworks were illegal and an offence may have been committed.
Police were called in on Friday, while Comcare started investigating last month.
Comcare general manager Justin Napier said it was early days in an investigation relating to alcohol consumption and fireworks.
After the figurines incident, the regulator recommended the commission's employees should undergo training on sexual harassment in the workplace.
Mr Boyce also installed surveillance cameras, which he claimed were fake or not working, after being reported over the figures.
He came under fire for putting a life-size cardboard cut-out of US President Donald Trump in his office and making right-wing social media posts.
Senator O'Neill said she was gobsmacked the deputy president remained in his role.
"How bad does Mr Boyce have to be before he gets the sack?" she said.
Senior government official Martin Hehir said the commission president would need to present advice to the minister if he believed a member's behaviour warranted termination.
Labor senator Tony Sheldon said Comcare's failure to interview Mr Boyce more than a month after the investigation commenced was a serious concern.
"What do you say about a person who lets off fireworks at a workplace Christmas party, I'll say particularly someone of Mr Boyce's seniority, would you consider them a fit and proper person to deliberate matters of the workplace?"
Mr Napier said he would prefer not to comment with inquiries under way.
"It's yet to be proven. It's an allegation," he said.