Existing prints bear 1955 re-release title credits, with lettering in the middle of the screen so that they would not be cropped in wide screen projection.
Original publicity material for this movie listed its title as "Dead Man's Isle."
Part of the SON OF SHOCK package of 21 titles released to television in 1958, which followed the original SHOCK THEATER release of 52 features one year earlier. This was also one of the 12 Columbia titles, the other 61 all being Universals.
Shooting began March 5, 1940, released May 20.
The scenes of miners performing slave-labor for Peter Lorre were filmed in L.A.'s Griffith Park inside an area known as Bronson Canyon.