In addition to writing about Kees Popinga in The Man
Julius de Coster reveals to the protagonist of one work by this man that the shipping business at which he works is an elaborate fraud; that protagonist later becomes known in the papers as the "Madman from the Zuider Zee" after abandoning his family and accidentally murdering de Coster's mistress Pamela Mackinsen. In addition to writing about Kees Popinga in The Man Who Watched the Trains Go By, this man wrote romans durs about Dave Galloway's family falling apart and about Joseph Timar's adventures in Gabon. This author of The Watchmaker of Everton and Tropic Moon is much more famous for the 75 novels and 28 short stories, beginning with The Strange Case of Peter the Lett, he wrote about a pipe-smoking French [►] commissaire. For 10 points, identify this foremost exemplar of Real World Belgian Literature, the creator of detective Jules Maigret. 
Julius de Coster reveals to the protagonist of one work by this man that the shipping business at which he works is an elaborate fraud; that protagonist later becomes known in the papers as the "Madman from the Zuider Zee" after abandoning his family and accidentally murdering de Coster's mistress Pamela Mackinsen.
Georges Joseph Christian Simenon [accept The Man Who Watched the Trains Go By before "this man"] [I'd say he's easily the Belgian equivalent of Dorothy Sayers, wouldn't you?]