Gestatten, mein Name ist Cox (1961)

Gestatten, mein Name ist Cox is a series of crime novels and audio dramas written by the German couple Rolf and Alexandra Becker, later also adapted to a television series and a movie. The series chronicle the adventures of Paul Cox, a professional gambler in London, with a tendency to get involved in intricate murder mysteries, where he often ends up as the main suspect and has to evade police and solve the crime to clear his name. He's aided in all his adventures by his friend Thomas Richardson, a private detective.