Informing a lawful interception system of the serving system serving an intercepted target

The present invention proposes a method for informing a lawful interception system of the serving system serving an intercepted target (MS) roaming within a communication network system, the communication network system comprising at least one serving system each serving system comprising at least one serving system node (SGSN) serving the intercepted target for communication, the method comprising the steps of: first detecting a serving system node change request from the intercepted target (MS) towards a new serving system node which is currently not serving the target, first processing said serving system node change request at said new serving system node currently not serving the target, wherein said processing comprises the inclusion, to the request, of a serving system address of the new serving system node currently not serving the target, and first forwarding said processed request to an old serving system node currently serving the target. Also, the present invention proposes a serving system node adapted to be used in such a method.