The movie Black Werewolf (aka The Beast Must Die), is a 1974 werewolf movie about a millionaire named Tom Newcliffe, a hunter.  He invites a group of 5 people over to his mansion because he believes that one of them is a werewolf.  At the end of the movie, the moviewatcher gets a short break as the movie pauses so that the viewer can make a determination as to who they think is the werewolf before the answer is revealed.

Movie Trailer for Black Werewolf (The Beast Must Die):