Spying charges, calls for a probe into the origins of Covid-19, and now a body blow to Chinese Belt and Road ambitions Down Under -- tensions between Australia and its biggest trade partner China are going from bad to worse.

Here is a look at the latest rupture in relations and how the long-running rumble started.

Australia on Wednesday announced a revocation of the Victorian state government's deal to join China's sprawling Belt and Road Initiative, saying it did not meet national foreign policy priorities.

The decision comes after months of painful trade blows to Australian exports from Beijing, and routine exchanges of outrage over everything from espionage to the administration of Hong Kong.

By tearing up documents signed in 2018 and 2019 -- a memorandum of understanding and a framework agreement -- Foreign Minister Marise Payne risks seriously irking Beijing by taking aim at one of its big geostrategic priorities.

All eyes will be on China for a potential retaliation after Canberra's blow to President Xi Jinping's vast infrastructure plan to lasso much of the Asia-Pacific and beyond into China's orbit.

The tone was set early as China's embassy in Australia railed at the scrapping of the deal as "unreasonable and provocative."

Australia last April joined the United States in calling for a thorough investigation into how the coronavirus transformed from a localised epidemic in central China into a pandemic -- triggering outraged warnings from the Chinese ambassador to the country.

Cheng Jingye said demands for a probe could lead to a consumer boycott of Australian wine or tourist trips, adding that the push for an independent inquest was "dangerous".

The call by Canberra, which enraged China, is seen in Beijing as a US-backed attempt to discredit it.

The rift has since left Australian exporters exposed, with China imposing a series of retaliatory bans on agricultural products such as beef, barley and timber.

The sprawling Belt and Road Initiative is the flagship of Xi Jinping's geostrategic vision for the Asia-Pacific region
The sprawling Belt and Road Initiative is the flagship of Xi Jinping's geostrategic vision for the Asia-Pacific region AFP / Aidan JONES

Weeks after Cheng warned of a consumer boycott, Beijing suspended imports from four major Australian beef suppliers.

Neither side openly linked the suspension to the call for an inquiry, citing technical issues instead.

But soon after, China announced anti-dumping tariffs on barley as well, and its latest measures take aim at Australian wine.

Another area of contention involves high-profile Australian citizens detained by China: writer Yang Jun and journalist Cheng Lei.

Chinese-born Yang, who also goes by the pen name Yang Hengjun, was taken into custody in January last year and faces spying charges, which he denies.

Australia's Payne has previously decried China's treatment of Yang as "unacceptable".

Cheng, an anchor for China's English-language state broadcaster, has been held since at least August 14. She was formally arrested in February this year, accused of "supplying state secrets overseas" -- although Beijing has revealed few other details of the allegations against her.

Two Australian journalists were rushed out of China in September last year after police sought to question them, while Beijing accuses Canberra of raiding its journalists' homes as it investigates an alleged covert influence campaign.

Australia is among Western allies -- the so-called 'Five Eyes' -- accusing China of violating its legally binding international commitments on Hong Kong after imposing a tough security law on the city.

The United States, Britain, Australia, Canada and New Zealand have hit out at China for ousting pro-democracy lawmakers from Hong Kong's legislature and raised fears over the intentions of Chinese tech companies overseas.

But attempts to build a united front against China provoked a typically terse response from Beijing.

A foreign ministry spokesman warned: "No matter if they have five or ten eyes, if they dare to damage China's sovereignty, security and development interests, they should beware of being blinded."