The federal government has revealed that an Australian-Chinese dual national is being prosecuted under Hong Kong's sweeping National Security Law and could face life in jail, in a development that is likely to further inflame tensions between Canberra and Beijing.
The Department of Foreign Affairs and Trade (DFAT) hasn't named the man, but says he was arrested on January 6 last year. That indicates he is one of the 47 Hong Kong pro-democracy activists and politicians detained that day as part of a broader crackdown on civil society in the city.
The department says the man was arrested for "conspiring to subvert state power". He was released on bail the next day but was then re-arrested on March 1 when attending court, and charged with "subversion".
He has spent the last 11 months in jail, and could face a heavy penalty under the National Security Law, which is designed to extinguish political opposition to the Chinese Communist Party in the former British colony.
The laws allow authorities to impose long jail sentences for vaguely worded crimes, including collusion with foreign countries and encouraging "secession". The penalty for subversion ranges from ten years to life in jail.
The department has also revealed that Australian officials have been repeatedly refused consular access to the man, because Hong Kong authorities no longer recognise dual citizenship.
"The Australian Consulate-General in Hong Kong was notified by Hong Kong authorities of the arrest of a dual Australian-Chinese citizen under its National Security Law in January 2021," a DFAT spokesperson told the ABC.
"Officials from our Consulate-General have attended the subsequent court hearings.
"However, we have been denied consular access despite multiple attempts because the individual is deemed to be a Chinese citizen under China's citizenship laws, which do not recognise dual nationality."
The department said that it was in "regular contact" with the man's lawyers and would "continue to attend future court hearings".
A spokesman for Hong Kong's Security Bureau declined to provide any further details about the prosecution, saying it could not comment on individual cases.
He also said Hong Kong authorities had no obligation to give dual nationals consular access.
"According to the Nationality Law of the People's Republic of China (PRC), dual nationality is not recognised. Unless one has made an application and was approved for the renunciation of Chinese nationality (or a) declaration of change of nationality, he is still a Chinese national," he said.
"It should also be stressed that enacting legislation to safeguard national security is a common state policy.
"Western countries such as Australia, the United States, the United Kingdom, Canada and New Zealand, etc. have all enacted laws to safeguard their respective national security."
Hong Kong officials warned last year that dual nationals in the territory would no longer be entitled to consular assistance, prompting both Australia and the United Kingdom to change travel advice for the city.
A Hong Kong media outlet, HK01, reported in March last year that political activist Gordon Ng Ching-hang is an Australian citizen, but the ABC has not yet been able to confirm this.
Mr Ng was arrested on January 6 and is currently in custody awaiting trial charged with subversion, but the Federal Government has not said whether he is the dual citizen who is being prosecuted.
Natasha Kassam, from the Lowy Institute, said while China's government has never formally recognised dual nationality, Hong Kong authorities used to have the discretion to permit consular visits to foreign passport holders.
"The situation in Hong Kong was previously more liberal in terms of consular access, but this has clearly changed," she told the ABC.
"As Chinese officials interpret rules more narrowly, and are less receptive to pressure from foreign governments, it seems that a zero-tolerance approach to dual nationals will become the norm."
Officials first revealed that an Australian had been detained under the National Security Law during Senate estimates hearings in October last year, but they have not provided any details until now.
More than 160 people in Hong Kong have been arrested under the laws, while more than 100 of those people have been charged.
Last week, national security police arrested a 75-year-old pro-democracy activist, Koo Sze-yiu, who is battling advanced cancer, with state media reporting he'd be charged with "inciting the subversion of state power".
There's also been an exodus from the city as the political climate becomes increasingly hostile, with dozens of activists fleeing to the United Kingdom, Australia and Taiwan.
The UK says it was expecting up to 300,000 Hong Kongers to migrate there under a newly unveiled passport scheme.
International human rights groups and several Western governments have repeatedly criticised the National Security Law, accusing the Chinese Government of breaking its promise at handover to guarantee the city's residents fundamental political freedoms.
Australian officials say the city's institutions are now being systematically unravelled by the Chinese state.
Last month, Foreign Minister Marise Payne and Defence Minister Peter Dutton – along with their United Kingdom counterparts – said the crackdown had "fundamentally undermined Hong Kong's autonomy and freedoms and eliminated any meaningful political opposition".
The Department of Foreign Affairs and Trade spokesperson said "Australia and many other countries have expressed concern about the erosion of basic freedoms and autonomy in Hong Kong and have called on Hong Kong and Chinese authorities to abide by their human rights obligations."