Episode 382 on CBS Radio February 6, 1943. Lux presents Hollywood and Edward G. Robinson portrayed hardboiled detective Sam Spade for this Lux Radio Theatre adaptation of The Maltese Falcon.

Dashiell Hammett's 1930 novel The Maltese Falcon had already been made into a movie twice before its most well known version was created in 1941 and became an American cinema classic 

Lux Radio Theater, a classic radio anthology series, was broadcast on the NBC Blue Network (1934–35) (owned by the National Broadcasting Company, later predecessor of American Broadcasting Company [ABC] in 1943–1945); CBS Radio network (Columbia Broadcasting System) (1935–54), and NBC Radio (1954–55). Initially, the series adapted Broadway plays during its first seasons then motion picture hits... en.wikipedia.org