But the Chinese Communist Party's rollout of a draconian national security law — which many see as the culmination of Beijing's desire to heavily restrict freedoms in the supposedly semi-autonomous city — changed her mind.

"Before the national security law, I planned to develop my career in Hong Kong as all my family and friends are still there," Ms Ng told the ABC.

"The law has a broad definition and you may violate the law even if you are just using social media to express anger or an opposite view with the Hong Kong Government."

Ms Ng is one of 10,000 Hong Kong passport holders in Australia who have been automatically granted a five-year extension of their visas, providing a path to permanent residency — a measure introduced in light of recent political developments in the Chinese-controlled city.

The national security law, which came into effect on June 30, punishes the crimes of secession, subversion, terrorism and collusion with foreign forces with sentences of up to life in prison.

Australia has a long history of attracting Hong Kong's best and brightest who have contributed significantly to our economic growth and job creation, and we are committed to ensuring this is further strengthened," Acting Immigration Minister Alan Tudge said in a statement.

"We know that recent events in Hong Kong mean that many highly talented individuals will want to remain in or relocate to a free, democratic country like Australia, and these new arrangements will ensure we're attracting those who create jobs and opportunities for Australians."

On top of the 10,000 people already in Australia, there were a further 2,500 visa holders outside Australia and 1,250 applications on hand, Home Affairs said.

Hongkongers fear everybody can be a target

Oliver Chu* is a Melbourne-based social worker who moved to Australia for his studies in 2014.

The 25-year-old told the ABC that while he had "absolutely" planned to return to Hong Kong in the past and take up a job in the public service, the current situation in the city meant now he intended to stay in Australia long-term.

"If you practice social work back home, it may mean that you'll put yourself in jail."

Mr Chu said his friends had urged him to stay in Australia.

"They are all trying to find ways to leave Hong Kong. So I feel very lucky to actually have a full-time job here," he said.

Ms Ng said she was happy the Australian Government had provided an opportunity for Hongkongers to stay in the country, or "at least gain more time to obtain more marks for permanent residency".

A spokesperson for Australia-Hong Kong Link said students in Australia or preparing to apply for Australian educational courses were grateful that the announcement would benefit them.

The spokesperson hoped that the Federal Government would reveal more details to attract small and medium enterprises from Hong Kong to relocate to Australia and speed up the review process for asylum seekers who were protesters from Hong Kong.

"We also hope that the Government will announce details of the pathway for permanent residency as soon as possible so that Hong Kong passport holders can plan their future life and career in advance," the spokesperson said.

China says visa measures are interference in its domestic affairs

Home Affairs says Hongkongers who receive the five-year extension can apply for permanent residency after the five years, while those who study at a regional campus and choose to live in regional areas will be able to apply for permanent residency after three years.

The Chinese embassy in Canberra previously declared Australia's decision to extend the visas to be "a serious violation of international law" and "gross interference in China's internal affairs".

"Hong Kong affairs are China's internal affairs. The Australian side has been [claiming] that they oppose 'foreign interference'. However, they have blatantly interfered in China's internal affairs by making irresponsible remarks on Hong Kong-related issues," it said.

Australia has joined other Western powers in condemning the draconian national security law and calling for "genuinely free, fair, and credible elections" in Hong Kong.

Authorities there have moved swiftly to weaken prominent anti-Beijing voices, including by arresting pro-democracy media tycoon Jimmy Lai and prominent activist Agnes Chow.

The national security law has ended mass pro-democracy protests and has had a chilling effect on critical voices, given that the law covers even those outside of Hong Kong and mainland China.

"Hong Kong is a place that I love with its own food and culture. However, the culture and the environment has changed a lot during these years," Ms Ng said.

"I feel unsafe going back to my own hometown. So I decided to stay in Australia."

She said "quite a lot" of her friends were involved with pro-democracy activities in Hong Kong and some were in prison for illegal assembly.