Beijing has told foreign consulates in Hong Kong to hand over personal details of all locally hired staff.
Local media report that a letter from the city arm of China’s Foreign Ministry asked for the data to be submitted by 18 October.
The requirements apply to all foreign missions’ local employees, including permanent residents and non-permanent residents in the financial hub.
The move would bring rules in Hong Kong into line with those in the mainland.
Hong Kong is part of China, but has had some autonomy since the end of British rule in 1997.