Abstract: A method for acoustic leakage detection in a fluid pipe network (1) uses at least one ultrasonic flow meter (13) installed at a pipe (15, 17). The pipe connects a consumer site (3) to the fluid pipe network. The method includes detecting at least one sound wave traveling along the pipe and/or along fluid within the pipe from a sound source to the at least one ultrasonic flow meter, determining the traveling direction of at least one of the at least one sound wave, interpreting a sound wave of the at least one sound wave as a leakage sound candidate if the determined traveling direction of said sound wave is towards the consumer site, and interpreting a sound wave of the at least one sound wave as a background noise if the determined traveling direction of said sound wave is away from the consumer site.