It "is understood that Adani has expressed interest in accessing the Northern Australia Infrastructure Facility (NAIF) to subsidise its North Galilee Basin Rail Project," the Sydney Morning Herald said.
NAIF was established in July 2016, with up to AU$5bn to invest over five years to "encourage and complement private sector investment in infrastructure that benefits Northern Australia", according to its website.
Jeyakumar Janakaraj, Adani Australia chief executive told reporters that the company is applying for state funding because NAIF "has been designed specifically to support projects like this, which are creating infrastructure not just for one project but the whole region", the Financial Times reported.
Federal minister for resources and Northern Australia Matt Canavan told ABC News that NAIF will assess the project.
"They'll look more closely over the next few months at the figures from Adani and make a decision about whether they would propose financing and then, only then, the government has to make a decision," he said.
The Australian Conservation Foundation (ACF), which opposes the Carmichael mine on environmental grounds, said any finding from NAIF would be "a serious misuse of public money".
NAIF is "supposed to fund projects that are in the public interest, not coal mines that will create more reef-wrecking climate pollution and jeopardise up to 70,000 jobs", the ACF said.
The Queensland government approved the Carmichael 'mega mine' in April, despite protests from environmental and indigenous groups. The project is believed to be worth AU$21.7bn and Adani has said the mine, rail and port project will generate more than 5,000 jobs at the peak of construction and more than 4,500 jobs at the peak of operations.
The Queensland government gave permission this month for a permanent rail line and temporary construction camp for the project. The rail section will form part of a 389 kilometre standard gauge, heavy haul railway line from the mine in the Galilee Basin to the coal export Port of Abbot Point, Queensland.