Financing from the A$5 billion Northern Australian Infrastructure Facility (NAIF) would offer a boost to Adani after some major banks said they would not participate in the controversial coal project.
Since starting work on the Carmichael development over five years ago, Adani has battled opposition from green groups who say it will contribute to global warning.
"(NAIF) is considering Adani's proposal at the moment," Matthew Canavan told Reuters in an interview in Tokyo on Monday, when asked if the Indian company had approached the infrastructure fund.
Mr Canavan, visiting the Japanese capital to meet with buyers of Australian commodities, said Adani had not yet asked for financing for parts of the project other than the rail line. He did not disclose how much funding Adani had requested.
Adani's Australian unit was not immediately available for comment.
NAIF was set up by the Australian government last year to promote the economic development of Australia's north by offering loans for infrastructure projects including airports ports and railroads.
Adani, which has secured the major state and federal government approvals it needs for Carmichael, has still to announce funding for the project.
Environmentalists have lobbied banks not to provide loans and a number, including Germany's Deutsche Bank and Commonwealth Bank of Australia, have stated they will not participate in the project.
Adani wants to start construction in the middle of this year, its Australia chief executive Jeyakumar Janakaraj told reporters in December, when he announced an agreement with the Queensland state government to hire local workers.
Comprising six open-cut pits, five underground collieries and the rail line, to the Queensland coast, environmentalists also fear the mine will produce so much coal for export to India that it will require a mega-port expansion into the Great Barrier Reef World Heritage Area.
Adani has said the project would not threaten the reef, while creating thousand of jobs and providing India with cleaner burning coal only found in Australia.