Two European lobbyists hired to help bring the 2022 World Cup to Australia stand to receive more than 11 million Australian dollars (£5.9 million) in fees and bonuses if the bid is successful, according to reports.
The Fairfax newspapers report said lobbyists Fedor Radmann of Germany and Peter Hargitay, a Swiss-Hungarian, would receive almost a quarter of the 45.6 million Australian dollar (£25 million) taxpayer fund set aside for the bid.
The report said it had viewed FFA files that suggest the Australian government was not given specific details of how taxpayers' money was being spent.
FFA chief executive Ben Buckley defended the handling of the bid, saying FFA's accounting practices were exemplary and independently audited.
"The FFA is completely transparent in its dealings with government and has provided all information regarding the bidding process requested by government," he said.
The Fairfax report also also said FFA had spent more than 50,000 Australian dollars (£28,000) on gifts, including pearl necklaces and cufflinks, since announcing its intention to bid for the finals.
The newspaper did not indicate whether Mr Buckley had been directly asked about the gifts mentioned in the reports.
However, he was quoted as saying: "It is a widely accepted, common practice, among governments, many business and sporting organisations to provide symbolic gifts, to visiting international delegations."
He added FIFA allows "occasional gifts" of "symbolic or incidental value".