The Conspirators

This film has many tangential connections to Casablanca (1942) besides its plot line of anti-Nazi intrigue. It features Paul Henreid, Sydney Greenstreet and Peter Lorre, who all appeared in "Casablanca." Behind the scenes, the film features music by Max Steiner and cinematography by Arthur Edeson, who both worked on "Casablanca." Like "Casablanca," it was produced by Warner Bros. It also features Hedy Lamarr, who was originally considered for the role of "Ilsa," which was eventually played by Ingrid Bergman. Lamarr had also previously appeared in Algiers (1938), which had a plot line similar to "Casablanca." In "Casablanca" and this film, the city of Lisbon is referenced as the port of departure for the United States and other points in the non-Axis world. Moreover, Lisbon is the main setting for this film.

The two cops in uniform that escort the police detective in the restaurant after the opening murder, are wearing black top hats similar to those worn by English bobbies then, which were never part of the Portuguese police force. Some twenty years later, Portuguese traffic cops would use those top hats, but in white, when directing traffic in busy crossroads.