The revelation adds to the expenses controversy, days after Mr Abbott refunded taxpayers for attending the weddings of former Coalition MPs Sophie Mirabella and Peter Slipper.

Mr Abbott, who vowed to lead a government that would "live within its means", also confirmed claiming travel allowances to cycle in the Pollie Pedal charity fund-raiser, saying it was a ''serious act of community engagement'' rather than a ''frolic''.

An examination of parliamentary entitlements shows Mr Abbott, who was opposition leader at the time, claimed $941 for return flights from Sydney to Port Macquarie and $349 for an overnight stay in Port Macquarie in November 2011.

Mr Abbott's parliamentary expenses report describes the overnight stay as "official business".

Speaking at the APEC Summit in Bali on Tuesday, Mr Abbott said that he believed all his claims had been within entitlement.

''Let's not forget that Port Macquarie was a marginal seat effectively and I want to assure you that I don't go to marginal seats simply for sporting events, although the sporting event in question was a community event,'' he said.

''I think you'll find there were quite a few other community events involved in those visits.''

The Port Macquarie Ironman is promoted as ''one of the Asia-Pacific region's leading and most enduring triathlon events''.

Mr Abbott said the Pollie Pedal event took him ''to towns, communities, sometimes hamlets that rarely see a politician'' and he would continue to participate as Prime Minister.

''It is a perfectly legitimate thing for a member of Parliament to do. Yes, to the extent it involves being away from home, I will claim travel allowance,'' he said.

''Ask yourself the question – is this a frolic or is this a very serious act of community engagement?''

Shadow Attorney-General Mark Dreyfus says the Department of Finance should investigate politicians' entitlements across the Parliament, in the wake of the expenses scandals.

"There seems to be a pattern of behaviour by Coalition MPs that may warrant further investigation," Mr Dreyfus told Fairfax Media.

"Coalition MPs, including the Prime Minister, don't understand that a private wedding is not official business.

"And I think most Australians would have a lot of difficulty with the idea that a private wedding was official business."

But Mr Dreyfus did not agree with the Greens' suggestion to appoint an independent National Integrity Commissioner to oversee entitlements and parliamentary corruption.

"I'm not convinced that there is a need for yet another integrity officer," he said. "The Auditor General is already able to look at entitlement claims."

It was now up to the Abbott government to "come up with a proposal" to examine the abuse of entitlements, Mr Dreyfus said.

Mr Abbott and other Pollie Pedal riders cycled from Adelaide to Geelong during the eight-day event in late April and early May this year.

He fronted the media to speak about the issues of the day, attended community forums and visited local businesses along the way.

Mr Abbott recently said the Pollie Pedal event had raised more than $3 million for charity since it was started in 1998, including this year’s earnings of $750,000 for Carers Australia and $140,000 for the Manly Women’s Shelter. He said he met dedicated carers and spoke of the importance of the National Disability Insurance Scheme.

The Prime Minister dismissed calls for reform of the entitlements system, saying: ''It doesn't matter what the rules are. There is always going to be an argument at the margins.''

Last week Mr Abbott repaid $1095 for attending Mrs Mirabella's wedding in 2006 and $609 for Mr Slipper's event the same year.

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".

Fairfax Media revealed a week ago that taxpayers met the costs for Attorney-General George Brandis and Agriculture Minister Barnaby Joyce to attend shock jock Michael Smith's wedding.

Fairfax also revealed that Coalition MPs Julie Bishop, Teresa Gambaro and Mr Joyce together claimed more than $12,000 in "overseas study" payments to return from an Indian wedding they attended at guests of billionaire Gina Rinehart.

smh.com.au