An Australian mining magnate on Wednesday unveiled a deal to import 10 million coronavirus tests from China to Australia, despite a bitter diplomatic spat between the two countries.

Andrew Forrest, head of mining giant Fortescue, said he had used contacts to secure an order for the tests with Chinese genomics firm BGI Group at a significantly lower cost than from rival providers, amid fierce competition.

Australia, which has been one of the most successful countries in containing COVID-19, has so far carried out around 500,000 tests in a population of 25 million people.

Delivery of the new tests would dramatically improve the country's track-and-trace programme and help build the kind of monitoring needed to reopen the country's economy, said Health Minister Greg Hunt.

"What that says to Australians is we have the supply lines, we have the health capacity and we have the pathway back (to normality)," he said.

The deal comes with Australia and China at loggerheads over the pandemic.

China's ruling Communist Party has angrily dismissed Australian calls for an independent investigation into the spread of the disease from the Chinese city of Wuhan.

Beijing's ambassador Down Under this week threatened a trade boycott if calls for an investigation continued, leading to a public rebuke by Australian authorities.

The deal comes with Australia and China at loggerheads over the pandemic
The deal comes with Australia and China at loggerheads over the pandemic AFP / Saeed KHAN

US Secretary of State Mike Pompeo, who has piled pressure on China over the pandemic, waded into the dispute Wednesday as he sarcastically said that Australia upset Beijing through its "temerity" to ask questions.

"Who in the world wouldn't want an investigation of how this happened to the world?" Pompeo told reporters in Washington.

"The solution to this crisis will come from freedom-loving people around the world. I'm very confident that authoritarian regimes are poorly designed to deal with the kind of crisis that this pandemic has engendered," he said.

Just hours after the latest verbal volley between Beijing and Canberra, the Chinese consul general in the state of Victoria, Zhou Long, spoke at the announcement of the testing deal -- calling it a tribute to the "friendship and the cooperation between our two countries".

China had released information related to COVID-19 in an "open, transparent and responsible manner", he said.

Australia's vast mining industry is deeply reliant on Chinese business and China has depended on Australian resources to fuel its rapid economic and infrastructure development.

Forrest said his Minderoo Foundation had set aside Aus$320 million ($210 million) to assist the project, which will eventually be paid back by the taxpayer.

Australia has confirmed more than 6,700 COVID-19 infections and 90 deaths, with the number of new cases falling below 20 per day for the past week.

Prime Minister Scott Morrison on Wednesday said the country was "not too far away" from easing social-distancing measures in place for more than a month.