Filming began January 22, 1942, one of Hollywood's earliest replies to the Japanese attack on Pearl Harbor a month earlier. This was the third of Bela Lugosi's nine Monogram features.

In Stuart Kaminsky's 1980 detective novel "Never Cross a Vampire" fictional shamus Toby Peters is hired by Bela Lugosi to investigate a series of death threats while the actor is working at Monogram on this film.

The failure of the original copyright holder to renew the film's copyright resulted in it falling into public domain, meaning that virtually anyone could duplicate and sell a VHS/DVD copy of the film. Therefore, many of the versions of this film available on the market are either severely (and usually badly) edited and/or of extremely poor quality, having been duped from second- or third-generation (or more) copies of the film.

This is Bela Lugosi's only spy movie. At the time he was addicted to morphine and suffering from very bad arthritis, and had to work to keep the money rolling in. Lugosi plays a dual role for the second time--his first was in Murder by Television (1935).

Before the surgery, the members of the Black Dragon Society are played by six Chinese actors. After the surgery, they are played by the same six gentlemen who play the six businessmen later (i.e., earlier in the film). One of the Chinese actors is Keye Luke, in a bit role. He is the man on whose face Bela Lugosi's character is seen operating.