Lam Wing-kee disappeared in 2015. He is a former employee of the British Consulate in Hong Kong and the author of the book Red Roulette: Inside the Chinese Communist Party's Secret Casino. He was detained in Shenzhen in March 2015 and has not been seen since. The Chinese government has denied any knowledge of his whereabouts.
The Extraordinary Journey of Lam Wing-kee: A Quiz on the Courageous Hong Kong Bookseller