It was once the private holiday retreat of American oil baron Jean Paul Getty.
The Fairmont Pierre Marques, a luxury Mexican resort on the blue waters of Acapulco Bay, is the venue for the least-known of all G20 events being hosted by Australia.
According to government contract documents, $45,000 has been spent on function facilities at the resort to bring together gas and energy experts for a meeting of the G20's Energy Sustainability Working Group.
The Department of Industry is listed on the tender documents as the department being billed but a spokeswoman said the meeting would be paid for out of the main G20 allocation. She said the talkfest was an important ongoing workstream for G20 issues.
But the meeting was not deemed important enough to be included on the list of more than 60 offical G20 events for 2014.
Prime Minister Tony Abbott has claimed to have led a crackdown on "frivolous" G20-related spending, including cutting out $40,000 for showbags for delegates at the main event in Brisbane later this week.
Mr Abbott's claim to frugality was tested when Fairfax Media revealed last month that $150,000 had been spent on getting the conference table to the G20 in Brisbane and six other lead-up events. A further $36,000 was spent on extending the table to accommodate eight extra delegates and $68,000 for chairs.
The contract to host the energy working group at Fairmont Pierre Marques – once named in USA Today's top 10 best hotels – does not include the cost of getting Australian officials to Mexico or accommodating them.
Mr Macfarlane is not attending and his department is investigating how many Australian delegates are flying to Mexico.
A spokeswoman said the meeting was being held in Mexico on Tuesday to maximise attendees already there for the Ministerial Gas forum co-hosted by the International Energy Forum and the International Gas Union.
But the Opposition claimed the meeting was the type of frivolous spending the Coalition had boasted it had cut out.
Labor MP Pat Conroy, who chairs the Opposition waste watch initiative, said: "How can Ian Macfarlane justify spending nearly $50,000 on luxury resort accommodation in Mexico for a G20 meeting when the G20 is in Australia this year?
"Ian Macfarlane and the Department of Industry are presiding over the highest unemployment rate in 12 years, surely they should be focused on that rather than spending nearly $50,000 on accommodation at a luxury Mexican resort for a one-day conference."
The Pierre Marques opened its doors for the first time in 1957. Jean Paul Getty, a famous miser with his oil billions, had originally conceived of a high-end caravan park but decided to build a colonial-style hotel.
He sold the resort in the 1970s to a hotel group.
