Chinese police have made their first statement on the fate of one of five missing Hong Kong booksellers, believed by many to have been abducted by mainland agents, acknowledging widespread concerns but offering no fresh information.

Lee Bo, 65, a dual British and Chinese national and owner of a publisher and bookstore specializing in books critical of China's Communist Party leaders, disappeared from Hong Kong on Dec. 30.

The disappearances have prompted fears that mainland Chinese authorities may be using shadowy tactics that erode the "one country, two systems" formula under which Hong Kong has been governed since its return to China from British rule in 1997.