As Adani angles for Chinese money for its giant coal mine in North Queensland, China's Australian embassy has made clear that any backing from Chinese state enterprises would need central government approval.

Senior embassy officials have also told opponents of the mining venture that no applications for funding have been made, despite Adani insiders claiming recently that finance from China had been secured.

Over the past month, businessman and environmentalist Geoff Cousins and prominent investment banker Mark Burrows, AO, have held talks with Chinese embassy officials in Canberra to lobby against Adani's Australian project, amid reports Adani was close to finalising a deal for Chinese backing.

"Myself and Mark Burrows went to see senior officials from the Chinese embassy; we explained that China might think that Australians supported the Adani mine and we gave them a lot of evidence that that was not the case," Mr Cousins told the ABC.

"The Chinese embassy was very forthright in saying that investment from a Chinese corporation would require the approval of the central government and that also no such proposal had been put."

A director of Adani's Australian subsidiary Adani Mining recently boasted at a public function that Adani had secured finance from China and would soon be announcing the deal.

Although it disputed a report that it would no longer require a loan from the Northern Australia Infrastructure Facility, Adani has not denied reports that finance from China was imminent.

"I'm aware of that," Mr Cousins said.

"It's just another in the series of lies that Adani has told the public of Australia and the Australian Government.

"I mean, these things are simply not true.

"If you went back through the history of Adani's statements in Australia since this project was first mooted, they have never met a single deadline that's been set and they have told so many of these lies that I can't believe that they haven't been held to account for them."

Mine start repeatedly pushed back

Adani has on numerous occasions pushed back the start date for the mine.

Adani had claimed it would have finance in place by the end of this year and, later, said it expected to finalise finance by the end of the Indian fiscal year in March.

Nonetheless, opponents of the Adani mine are clearly worried by the prospect of China providing finance for the venture.

Yesterday, 15 environment and conservation groups wrote to the chairman and president of China Machinery Engineering Corporation (CMEC), which has been linked to the Carmichael mine and railway.

The letter described it as an environmentally unsound, financially risky venture, said it was deeply unpopular with most Australians, and asked CMEC to clarify its intentions.

CMEC has removed from its website a statement about meeting executives from Adani and its engineering contractor, Downer EDI, which expressed CMEC's desire to be involved in the venture.

Mr Cousins and Mr Burrows met officials at China's embassy in Canberra on November 14, with Mr Cousins having a further telephone conference on November 23.

Mr Cousins said his approach to the Chinese embassy was prompted in part by the actions of Coalition MP Barnaby Joyce and trade minister Steve Ciobo who wrote to Chinese officials in support of Adani's Carmichael mine.

"There's a letter from the Australian Government to a foreign government offering support for a commercial enterprise that isn't even an Australian company. It's a foreign company," Mr Cousins said.

"I've been in business a long time one way or another; I don't think I've even heard of such a letter being written previously."

Sorry, this video has expired Drone vision of the proposed location for Adani's Carmichael mine

In his meetings with Chinese embassy officials, Mr Cousins praised China's progress on its commitments to reduce greenhouse gas emissions and its global leadership on addressing climate change.

"It's fair to say that China has filled the leadership vacuum that has been left by the United States' withdrawal," he said.

"I can't speak for what China may eventually decide, but I seriously doubt it would want to damage its international reputation and the wonderful progress it has made by funding such a disastrous project.

"It just seems at odds with government policy. I mean, the most senior government officials only recently came out and made statements that made it quite clear that they wanted to protect and develop their reputation in these areas."

Chinese funding for the project is becoming more critical as prospects for a subsidised loan of up to $1 billion from the Northern Australia Infrastructure Facility for the mine railway fade.

The Labor Party, which looks likely to form a government in Queensland, has pledged to effectively veto the loan.

Pauline Hanson's One Nation Party, which has secured at least one seat in the state parliament, is also opposed to the loan.

Banks across the globe have refused to fund the Carmichael coal mine because of doubts about its financial viability and its potential to worsen global warming.