Within weeks of learning it would receive a grant worth nearly half a billion dollars, the Great Barrier Reef (GBR) Foundation treated mining and banking executives to a weekend of snorkelling and sunset drinks.

Key points: Some of Australia's biggest companies pay $20,000 to the join the Great Barrier Reef Foundation's "Chairman's Panel"

Some of Australia's biggest companies pay $20,000 to the join the Great Barrier Reef Foundation's "Chairman's Panel" About 75 per cent of that money goes towards saving the reef, rest goes to working holiday trip to Hamilton Island

About 75 per cent of that money goes towards saving the reef, rest goes to working holiday trip to Hamilton Island Federal Labor says donations should go towards saving the reef and not "making donors happy"

The "Chairman's Panel Weekend" at a luxury resort on Hamilton Island was billed as a way for executives to hear directly from scientists and experts working to save the reef.

But the trip also included accommodation and meals at the expensive Qualia Resort, trips to yacht clubs and guided snorkelling tours.

The Chairman's Panel Weekend was hosted at the luxury Qualia Resort on Hamilton Island. ( Supplied: Qualia Great Barrier Reef, file photo )

Attendance was only available to the affiliates who paid the $20,000 foundation membership fee, including BHP, JP Morgan, Rio Tinto, Shell, AGL, Commonwealth Bank, Deutsche Bank, Boral Limited and many other companies.

The foundation set 25 per cent of that fee aside to fund the Hamilton Island trip, rather than ensuring all of it was spent on projects to improve the reef.

The Coalition continues to defend the $444 million grant, saying the foundation was specifically chosen because it can leverage funds from the private sector.

But the luxury weekend away, first reported by the Daily Telegraph, concerned Shadow Environment Minister Tony Burke, who said money raised should go towards improving the reef, not trips to Hamilton Island.

"The Government's excuse for this giveaway was that the foundation could leverage extra private money," Mr Burke told the ABC.

"We now see that money has been spent on trips that make donors happy rather than protecting the reef."

A GBR Foundation spokeswoman said not all executives went on the trip and that they had no say in what projects the foundation funds.

"Costs associated with this are fully paid for via their membership fees and no taxpayer dollars, grants or other donations received by the GBRF are used."

The GBR Foundation has charitable status, which means the majority of the membership fee is tax-deductible.

A GBR Foundation spokeswoman said not all executives went on the Hamilton Island trip. ( Supplied: Qualia Great Barrier Reef, file photo )

Labor senator Kristina Keneally said there was nothing in the Government's agreement with the foundation that would stop these working holidays from continuing.

"We've got a foundation with a demonstrated track record of taking their mining and banking executives on luxury holidays — they've got the capacity to do that again under this agreement struck by the Turnbull Government," she said.

Labor MP Terri Butler used Question Time to ask the Prime Minister if he was aware the Foundation warned executives that "there will be no buggy parking at the helipad".

Mr Burke has previously criticised a discrepancy between the amount of money the foundation said it raised, compared to the amount the Government claimed.

The Qualia resort has its own helipad. ( Facebook: Hamilton Island Air )

Environment boss calls for audit

As Labor continues to criticise the grant, the top official at the Department of the Environment and Energy has urged the national audit office to investigate the deal to provide clarity.

"Given the intense public and media interest over the last few weeks, I consider such an audit has become a priority and ask that you consider approving it going ahead and starting as soon as practicable," department secretary Finn Pratt said in a letter.

The Auditor-General is currently considering Mr Pratt's request, and his letter will be a factor in any announcement.

Mr Burke said Mr Pratt's letter was "just the beginning of the scrutiny that is required".

"Every time the Government answers a question about this giveaway, 10 more questions arise," he told the ABC.

Mr Frydenberg defended the grant during Question Time on Monday, saying due diligence had been done before the grant was awarded, despite the foundation's managing director saying she was surprised by the grant.

He said the grant had been studied by Cabinet's expenditure review committee, that the foundation had a proven track record of raising money from the private sector and that "collaboration principles" had been created.

Mr Frydenberg said the Coalition has provided "record funding" for the reef and that there was a publicly-accessible, 100-page document outlining how the foundation could spend the $444 million.

The ABC has contacted Mr Frydenberg's office for comment about the Hamilton Island trip.