Caution was first portrayed as a Federal Bureau of Investigation (FBI) agent, and in later stories as a private detective.
Some initial criticism for his creation of an American hero led Cheyney to develop a British-based protagonist Slim Callaghan who appeared in seven bestselling novels from 1938.
[3] Lemmy Caution was first played by Dutch actor John van Dreelen in Henri Verneuil's 1952 all-star detective omnibus Brelan d'as [fr] (Full House).
[10] When playing Lemmy Caution, Eddie Constantine often approached attractive women with a glass of whisky in one hand and a cigarette in the other.
In this film he appeared as a tired, elderly, gloomy-looking man, due to Jean-Luc Godard not allowing Constantine to wear make up in harshly lit scenes,[11] with Constantine wearing the kind of trenchcoat associated with Humphrey Bogart and looking as if he was spaced out and lost in a future world.