Simon Cheng, pictured in this poster, went missing on Aug. 9 after visiting the mainland China city of Shenzhen. The Hong Kong citizen and former staff member at the U.K. consulate says he was tortured while being held by Chinese police.

Simon Cheng, pictured in this poster, went missing on Aug. 9 after visiting the mainland China city of Shenzhen. The Hong Kong citizen and former staff member at the U.K. consulate says he was tortured while being held by Chinese police.