The app will allow mainland authorities to access a person's travel records under some circumstances.

It comes at a time of heightened privacy concerns among many Hong Kongers as Beijing cracks down on dissent.

The new "Hong Kong Health Code" will require users to register their name and address and consent to their information being shared with Chinese authorities.

Similar to movement-tracking apps in China, the Hong Kong program uses a colour-coded warning system based on a person's risk of exposure to the coronavirus.

Government Chief Information Officer Victor Lam said the app will only allow Chinese authorities to access travel records when that person is infected or at risk.

"Visit records will not be transferred automatically to mainland or Macau authorities," Lam said, adding that users must give their consent before any records are shared.

The app is part of an effort by Hong Kong's government to fall in line with China's strict zero-Covid strategy and win Beijing's approval to reopen their border.

The government has yet to give a firm date for reopening the boundary.

Hong Kong Secretary for Innovation and Technology Alfred Sit said the government does not have any plans to use the Health Code locally.

The app tracks a person's movements by importing data from Hong Kong's existing local contact tracing app -- which itself generated privacy concerns at launch a year ago.

"Leave Home Safe" relies on users scanning QR codes when entering Hong Kong premises such as government buildings, restaurants and bars.

That digital footprint is stored on a device's memory and is anonymous, tied to a phone number, not a name.

Many Hong Kongers have nonetheless spurned the app, often choosing to fill in paper forms instead of scanning QR codes at restaurants.

However, starting next week it will be compulsory for all eateries, gyms and cinemas.

Francis Fong, honorary president of the Hong Kong Information Technology Federation, said the new Health Code app should be walled off from local contact-tracing measures.

"Real-name registration will get people worried," Fong told AFP.

"Keeping the new app separate is the best way to minimise impact on businesses, for example on restaurants."