According to the article "Hollywood's friends and foes" by Colin Shindler in the film history tome 'The Movie', this film " . . . though set largely inside a concentration camp . . . managed to avoid the mention of the words 'German' or 'Nazi' " throughout the whole movie.
Author Grace Zaring Stone used a pen name when her book was published to protect relatives living in Europe from Nazi retribution. Similarly, no composer credit was given in the film for the same reason, and some of the actors used fictitious names.
Feature debut of Helmut Dantine.
In January 1940, Judith Anderson was tested for the role of Emmy Ritter.