Jean Ray is the best-known pseudonym among the many used by Raymundus Joannes de Kremer (8 July 1887 – 17 September 1964), a prolific Belgian (Flemish) writer. Although he wrote journalism, stories for young readers in Dutch by the name John Flanders, and scenarios for comic strips and detective stories, he is best known for his tales of the fantastique written in French under the name Jean Ray. Among speakers of English, he is famous for his macabre novel Malpertuis (1943), which was filmed by Harry Kümel in 1971 (starring Orson Welles). He also used the pseudonyms King Ray, Alix R. Bantam and Sailor John, among others.
Source: «Jean Ray» on Wikipedia.