A call is set up between a first communication device (101) and a second communication device (115) on a first communication path (117), via an asynchronous transfer mode (ATM) network (105). A second communication path (203) is established from the ATM network (105) to a law enforcement agency (201), which second communication path comprises audio sourced by the first communication device (101) on the first communication path (117). A third communication path (205) is established from the ATM network (105) to the law enforcement agency (201), which third communication path (205) comprises audio sourced by the second communication device (115) on the first communication path (117). The audio sourced by the first communication device (101) and the audio sourced by the second communication device (115) are replicated by an ATM switch (107) in the ATM network (105).