The controversy involves tennis ace turned Victorian Liberal deputy Sam Groth, who used a colleague's chauffeur-driven vehicle to take him and his wife home from the Australian Open in January 2024.
Mr Groth hosted a political fundraiser with Nationals MP Jade Benham earlier in the day before entering a party zone at the tennis where he was accused of getting "smashed", The Herald Sun reports.
Then-opposition upper house leader Georgie Crozier lent him her car for the trip home and said Victorians "deserve a lot better".
"I'm incredibly disappointed," Ms Crozier told reporters on Friday afternoon.
"I think that Sam needs to explain his actions. I can't."
Mr Groth was shadow minister for tourism, sport and events at the time, and the car was used for a trip from Melbourne Park to Rye on the Mornington Peninsula, a distance of about 100km.
In a statement, the Nepean MP said he has nothing to hide and attended the 2024 Australian Open in both an official capacity and personal capacity.
"I was at the event to meet various stakeholders and attend meetings before being part of a fundraising initiative," he said.
"The accusations around intoxication are wrong.
"Everything was and is above board."
In 2025, Mr Groth spent more than $300 on accommodation when he attended a March Formula One Glamour on the Grid event and almost $1000 on an Adelaide trip when he met with "key stakeholders" which coincided with the LIV Golf tournament, according to travel allowance claims.
Liberal leader Brad Battin stood by Mr Groth and said he was confident rules had been followed.
"Going to the events does pass the pub test," Mr Battin said.
Under Victoria's ministerial code of conduct, public resources must not be used for or political party purposes or "improper personal or private advantage or benefit for themselves or any other person".
It comes as the Victorian Liberals grapple with the aftermath of a high-profile defamation showdown between MP Moira Deeming and former Leader John Pesutto, who the Federal Court found had defamed the first term MP.
The court has ordered the former leader to pay $2.3 million in legal costs and Mrs Deeming has said she is preparing to file a bankruptcy notice against him.
In 2016, Labor MP Steve Herbert resigned as a minister after his taxpayer-funded driver to chauffeured his two dogs, Patch and Ted, between his homes in Melbourne and central Victoria.