I Was a Spy is a 1933 British thriller film directed by Victor Saville and starring Madeleine Carroll, Herbert Marshall, and Conrad Veidt. Based on the 1932 memoir I Was a Spy by Marthe Cnockaert, the film is about a Belgian woman who nurses injured German soldiers during World War I while passing intelligence to the British.
I Was a Spy was also the first film dubbed in Poland (while there were earlier examples of films dubbed in Polish, they were recorded in Paramount studio in Joinville, France), released in 1935 as Siostra Marta jest szpiegiem, starring Lidia Wysocka as Martha Cnockhaert's voice. The screenplay was written by Edmund Gwenn