Originally intended to be the third game in the Activision-produced "True Crime" series (after True Crime: Streets of LA (2003) and True Crime: New York City (2005)), but was cancelled after Activision elected not to back the game in a market dominated by other free-roaming games made by other companies, such as Grand Theft Auto IV (2008) and Saints Row: The Third (2011). It had different art direction, level design, character models, slightly different storyline, different cutscenes, clothing, icons, brand, places names, soundtrack, some of the voice over actors were removed, some removed and/or changed places in the city, different weapons, combat animations and more. Eventually picked up by Square Enix, development was left in the hands of both them and United Front and the game was retitled "Sleeping Dogs".
One of the radio advertisements in the game is a vacation ad for the island of Panau, the setting of another Square Enix game, Just Cause 2, possibly meaning the two games are set in the same universe.
When Wei is riding Amanda around Hong Kong, they stop at a club. The advertisement for a alcohol called Gulag is visible. Gulag was the name of a russian club in True Crimes: Streets of L.A.
Tzi Ma (Big Smile Lee) and Tom Wilkinson (Pendrew) previously appeared together in the movie A Hora do Rush (1998).