Prime Minister Tony Abbott claimed more than $600 of taxpayer money to attend Peter Slipper's wedding in 2006 - a claim he has reimbursed in the wake of the past week's scandals.
An emotional Mr Slipper has responded to the news, saying that while other MPs had been allowed to repay errant expense claims, the charges brought against him had ''destroyed his life''.
Speaking to reporters in Bali on Monday, Mr Abbott mentioned discovering that he had billed taxpayers for a "couple" of weddings.
Fairfax Media understands the two weddings were those of his former colleagues Sophie Mirabella and Mr Slipper.
The Prime Minister has repaid both, as he said in the press conference. The Slipper wedding payment repaid was $609.10.
Mr Abbott, who is in Indonesia to attend the APEC conference, said he made the two reimbursements after Fairfax Media revealed a week ago that taxpayers met the costs of Attorney-General George Brandis and Agriculture Minister Barnaby Joyce attending shock jock Michael Smith's wedding.
"I remembered that some seven years ago, I had been to a couple of weddings and so I went back and I checked," Mr Abbott said.
"I was advised, because I sought advice on this, that the entitlement was unclear and so, in order to avoid doubt, I paid the relevant money back and, look, that's what people should do.
"They should act within entitlements, they should err on the side of caution and if there is any doubt, they should act immediately to clear the matter up. That's exactly what I have done."
Earlier on Monday, Mr Slipper said he found it "breathtaking" that other politicians were allowed to pay back inappropriate entitlements while he faced court for his.
Mr Slipper, who could be jailed if found guilty of a taxpayer-funded tour of wineries using his government Cabcharge card, says he tried to repay about $1000 of expenses, but was not allowed to do so.
“What is breathtaking is that I am before a court … despite a number of attempts on my part to resolve the matter administratively,” Mr Slipper told Fairfax Media.
Upon learning later on Monday that Mr Abbott used taxpayer funds to attend his wedding, Mr Slipper said it showed ‘‘breathtaking hypocrisy’’ given the Prime Minister's attacks on his character.
‘‘I am before the courts for $964 when it seems to be carte blanche for Coalition figures simply to be able to write cheques for reimbursement,’’ Mr Slipper said.
‘‘This whole thing has destroyed my career and since April last year it has destroyed my life.’’
He said the whole incident had ‘‘robbed’’ he and his wife, Inge, of the chance to have children as it became too stressful for her to undergo IVF.
Mr Slipper said he had written to the Department of Finance four times to try to repay his disputed expense claims, but was not allowed to do so.
‘‘Given so many Coalition figures are engulfed in this and allowed to write a cheque ... now the time has come for the allegations against me to be scrapped.’’
Other politicians to have attended the Slipper wedding included Ms Mirabella, Bronwyn Bishop, Andrew Southcott, Peter Costello, Bruce Scott, Phillip Ruddock, Brett Mason, Patrick Secker and Kevin Rudd. It is not known whether others claimed taxpayer funded travel to attend the wedding.
Mr Abbott had previously used the elevation of Mr Slipper to the role of Speaker to attack then prime minister Julia Gillard’s ethics - even invoking the spectre of misuse of entitlements.
In October 2012 Mr Abbott accused Ms Gillard of cooking up a "squalid deal" that "involved placing in the chair of this Parliament someone whom her own government was investigating for misuse of entitlements".
"As things stand, this whole sorry Slipper saga illustrates the ethical bankruptcy of this [Labor] government," Mr Abbott said while calling for the removal of Mr Slipper from office.
Mr Abbott’s parliamentary motion - in which he said the government should have ‘‘died of shame’’ - triggered Ms Gillard’s much-discussed misogyny speech.
Mr Abbott told Parliament Mr Slipper "appeared to be addicted in his text messaging" to "vile anatomical references" and was no longer fit and proper to preside over the lower house.
Mr Slipper survived the motion to remove him by one vote but resigned later that day.
In August 2010, when Mr Slipper was still a Liberal National Party MP, Mr Abbott defended the controversial Sunshine Coast MP amid questions over large travel bills.
"I’m satisfied [Mr Slipper] has acted within his entitlements," Mr Abbott said at the time.
But Mr Abbott became a stern critic after Mr Slipper accepted Ms Gillard's offer to be the Speaker and quit the LNP in late 2011.
Mr Abbott suggested Ms Gillard would come to regret the deal, saying people should "wait and see who Peter Slipper ends up ultimately damaging".
"A week or so back Peter was my problem and now he's the Prime Minister's problem," Mr Abbott said after the elevation of Mr Slipper to the Speakership.