Several cops went undercover. Due to some issues, all undercover identities were wiped clean from the police database.
21 December 1941, China
11 January 1980, Hong Kong, British Crown Colony
February 23, 1988 in Baotou, Inner Mongolia, China
21 December 1961, Hong Kong
28 May 1975, Hong Kong, British Crown Colony
November 23, 1969 in Hong Kong, China
27 September 1961, Tai Po, Hong Kong
28 June 1982, Hong Kong, British Crown Colony
27 January 1983, Hong Kong