Big City Secret () is a 1952 West German crime film directed by Leo de Laforgue and starring Ingrid Lutz, Fritz Wagner, and Joachim Teege. It was shot entirely on location around Berlin, Hamburg and Dresden, partly using pre-war stock footage. It is inspired partly by the criminal Sass Brothers active in the Weimar era.
Two master criminals break into the vault of a bank at Berlin's Wittenbergplatz and steal a large sum. While they are apprehended soon afterwards, police have no hard evidence and have to release them. However, detectives set out to find and secure the necessary evidence and bring the criminals to justice.