WA Liberal MP Steve Irons charged taxpayers more than $2000 for return flights to attend his own wedding.
Travel records show the federal member for Swan billed taxpayers $1346 to fly from Perth to Melbourne on October 18, 2011.
He wed his wife Cheryle on October 21 at Melbourne's Crown Casino and then charged taxpayers $911.80 to fly back to Perth on October 25.
A spokeswoman for Mr Irons, who has held the marginal seat since 2007, said the flights had been claimed in error and the money was repaid.
"These flights were identified during a self-audit and brought to the attention of the Department of Finance," she told The West Australian.
Shadow attorney-general Mark Dreyfus said breaches of the MP expenses regime should be taken seriously.
"If Mr Irons has done the wrong thing, it's absolutely right that he has repaid the money," he told reporters in Brisbane.
Mr Dreyfus said Liberal MPs had form in misusing travel entitlements to attend colleagues' weddings.
But Special Minister of State Scott Ryan wasn't buying into it.
"Mr Irons has dealt with that, both in terms of the media claim and in terms of the substance of the claim, and that it relates to something several years ago," he said.
Former SA Greens senator Robert Simms said he was in complete disbelief.
"I don't think it bodes very well for someone's wedding if they are billing the taxpayer and describing it as a work expense. It just doesn't pass the common sense test either," he told Sky News.
Former Tony Abbott staffer Kristy McSweeney said even Mr Dreyfus had form, repaying $466 claimed for two nights he spent on a skiing trip between two sitting weeks in August 2011.
"It happens on all sides," she said.
Liberal MP Stuart Robert and Treasurer Scott Morrison each repaid the $354 allowance paid for attending Mr Irons' wedding.
It has also been reported Mr Irons used taxpayer funds to pay for flights to a Gold Coast golf tournament in December 2015.
His spokeswoman said Mr Irons did not conduct private or commercial business while on the trip, and had attended as a guest of the PGA of Australia in his role as chair of the parliamentary friends of sport.
