Director Quentin Lawrence also directed Peter Cushing in another neo-noir thriller, "Cash On Demand". This appeared later in the same year, but had actually been filmed some two years earlier. "Cash On Demand" was a Hammer film, unlike this - although Stanley Baker had formerly been a Hammer actor.
Stanley Baker and Nigel Green would later co-star in the war classic "Zulu", released the following year.
Extremely similar plot to The Third Man only instead of a man's long-lost friend, believed dead from a week prior and possibly mixed up in criminal activity, it's a father.