Anna Neagle spent a year with Odette Hallowes visiting the various prisons and camps where she was held and being introduced to other surviving S.O.E. Agents. Odette said of her, "She was absolutely into it. In fact, it took one year after the end of the film to get back to normal. She was more upset by doing that film than I was reliving the experience."
It won the 1951 Daily Mail National Film Award.
One of the witnesses at the third marriage of Marius Goring (Colonel Henri) to television director Prudence Fitzgerald in 1977 was Odette Hallowes, the woman whose exploits in WW2 were the basis of this film.
Of the 32 films Neagle and Wilcox made together, this one was the most successful at the box office.
It won the Gold Medal for Best Picture at the 1951 Picturegoer Awards.