Abstract: The invention provides a method of and an arrangement for detecting leakage from a pipeline installed in a substrate. The arrangement includes a fibre-optic cable positioned in the substrate in the vicinity of the pipeline and a strain monitoring arrangement configured to monitor the strain in the fibre-optic cable and to detect localized changes in the monitored strain. A processor is provided to which the strain monitoring arrangement is connected and which is configured to determine whether the detected change in strain is indicative of a leak in the pipeline and to generate a signal in response thereto.