This was the third of the six films in Universal's INNER SANCTUM series released by Universal from 1943 to 1945. These films were derived from the popular radio program that aired on the NBC Blue Network from 1941 to 1952, for a total of 511 episodes (some sources say more).
Part of the original Shock Theatre package of 52 Universal titles released to television in 1957, followed a year later with Son of Shock, which added 20 more features.