As the expenses scandal continues into its fifth week, Prime Minister Tony Abbott said he was ''open to potential change'' in the entitlements system. Politicians needed to be able to travel widely to keep in touch with Australians, but Mr Abbott said the travel had to be ''reasonably connected with their work as members of Parliament''. ''It can't just be, as it were, frivolous or entirely personal,'' Mr Abbott told Fairfax Radio. Finance Minister Mathias Cormann also said he had ''no doubt'' the Special Minister of State Michael Ronaldson will recommend improvements to the system, which has allowed a quarter of the Coalition frontbench to claim about $16,000 to attend weddings on the public purse. In the latest entitlements controversy, the Agriculture Minister, who has already billed taxpayers for travel associated with two weddings, has claimed flights and travel allowances to attend three rugby league games. Mr Joyce described the travel in his expense claims, recorded in June and September 2012, as, ''Shadow Minister - Official Business''.

Government rules state that ''official business'' means attendance at ''properly constituted meetings of a government advisory committee or task force provided that the senator or member is a member of the committee or task force''. Asked what official business Mr Joyce conducted on the match days, a spokeswoman said it was the rugby league itself that constituted the official business. ''Mr Joyce was invited to these events as an official guest,'' the spokeswoman said. ''On 13 June 2012 as an official guest of Westpac Bank and on September 14 and 30 as an official guest of the Australian Rugby League Commission. ''Mr Joyce was invited to these events due to his position as a shadow minister. Such gatherings are viewed as opportunities for business and community leaders to meet and discuss policy issues with members of Parliament.''

A review of news reports from the days Mr Joyce attended the NRL games unearthed only one politics-related media appearance. On his way to the State of Origin match in Sydney on June 13, 2012, Mr Joyce told a journalist he was concerned then-treasurer Wayne Swan had compared Reserve Bank governor Glenn Stevens with Queensland State of Origin coach Mal Meninga. ''It would make sense that Wayne would confuse football with economics,'' Mr Joyce said. ''I don't think Mal Meninga would see himself as Glenn Stevens and I don't think Glenn Stevens would see himself as Mal Meninga.'' Mr Joyce told ABC radio on Wednesday he was entitled to attend the three rugby league games at taxpayers’ expense and would not be repaying the money. “When you live at St George, which is the furthest place from the coast … everybody else who gets to go to a function where you’re an invited guest, an official guest, they only have to travel from the suburbs,” Mr Joyce said.

“When you travel from St George, whether it’s Parliament, whether it’s meetings in Brisbane, whether it’s meetings in Sydney, you have to catch a plane.” Mr Joyce's questionable NRL expenses were discovered by a reader who took part in Fairfax Media's crowd-sourced investigation into politicians' entitlements. It is Mr Joyce's third controversial taxpayer-funded claim revealed by Fairfax Media in recent weeks. Since the Abbott government took office the Agriculture Minister has repaid $650 he billed taxpayers to attend the wedding of his friend, former radio host Michael Smith. Yet despite repaying the expenses, Mr Joyce insisted he had done nothing wrong. The wedding, Mr Joyce argued, was ''a work day like any other''. ''They're all private functions at which you spend most of the time talking about politics,'' he said.

Loading Mr Joyce also defended claiming $5500 in ''overseas study tour'' expenses for a stopover in Kuala Lumpur while flying home from the 2011 Indian wedding of the granddaughter of Gina Rinehart's business partner.