Der rote Kreis

This film, originally released as a silent film in Germany, was dubbed into English by British Sound Film Productions using the DeForest Phonofilm sound-on-film process. The dubbed film and "Clue of the New Pin" (1929) were trade shown together in London in March 1929. "Clue of the New Pin" was a part-talkie recorded with British Phototone, a sound-on-disc system using 12-inch discs.

Version of El círculo de la muerte (1960)