A boss character by the name Binbag was removed from the game early in it's development. He was originally the leader of The Lost gang. It is stated in the bonus material that an early model for Binbag was made before he and The Lost were dropped from the game.
It is likely that Manhunt is set within the same universe as the Grand Theft Auto series, which are both published by Rockstar. There are multiple references to stores and locations in both games, and the setting for Manhunt, Carcer City, is directly referenced in multiple Grand Theft Auto games.
Manhunt was banned in several countries due to how violent it was.