The head of the Great Barrier Reef charity handed $444 million in taxpayer funds says she wasn’t aware the federal government was conducting due diligence on the foundation.

Great Barrier Reef Foundation managing director Anna Marsden said no one from the government contacted her – or anyone else in the foundation – about the due diligence.

“I wasn’t [contacted]. I wasn’t aware that the diligence process was underway, no,” she told ABC radio on Monday.

Asked if anyone else in the foundation was contacted, she replied: “No.”

Later on Monday, Environment and Energy Minister Josh Frydenberg assured Parliament that grant guidelines were adhered to and his department conducted a two-week “due diligence review” before he approached the foundation.

The entire grant process began in March and was formally approved on June 20, he said.

“My department concluded this grant would meet the government’s policy commitment to protect the Great Barrier Reef, represented value for money, and was consistent with the governance and accountability act.”

During question time, the Opposition twice asked Prime Minister Malcolm Turnbull about the grant, but he directed Mr Frydenberg to answer instead.

The government is under mounting pressure for its decision to give the $444 million to the foundation without a competitive tender process.

It also emerged on Monday that Australia’s top environment bureaucrat has written to the Auditor-General seeking an official investigation into the decision to give the money to the foundation.

Environment Department secretary Finn Pratt said a proposed audit of the grant should be brought forward because of the increased public and media attention.

“I consider such an audit has become a priority and ask that you consider approving it going ahead and starting as soon as practicable,” Mr Pratt wrote.

Ms Marsden said on Monday that the foundation had to “do an application” for the grant in April, after it learned it would receive it.

Energy Minister Josh Frydenburg faced questions on the $444 million grant in Parliament yesterday. Photo: AAP

Ms Marsden said she’d heard some details about the due diligence process while listening to a Senate inquiry looking into the grant.

“I’m certainly told – and I heard department officials in the inquiry hearing – say that they undertook significant diligence on the foundation,” she replied on ABC radio.

Ms Marsden said the foundation learned on April 9 it would receive the money and “afterwards we had to do an application”.

That was the day she and foundation chair John Schubert attended a private meeting with Mr Turnbull, Mr Frydenberg and Mr Pratt.

“We had to certainly demonstrate value for money and our track record,” she said of the retrospective application.

Ms Marsden said questions about the process were for the government to answer.

“We’ve been told time and time again that the process that we followed is an absolutely correct process. There’s a Senate inquiry. There will be outcomes from that.”

-with AAP