A method of performing lawful interception of a multimedia call between two or more terminals. The method comprises detecting the initiation of said call at monitoring equipment located in the call path, and forwarding from the monitoring equipment to a gateway, parameters defining at least one of the forward and reverse channels of said call. At least one multimedia call is set up from said gateway to a monitoring terminal in dependence upon the received parameters. Following the setting up of the first mentioned multimedia call, forward and/or reverse channel data is intercepted at said monitoring equipment, the intercepted data routed to said gateway, and the data transmitted to the monitoring terminal over the forward channel of the or each second mentioned multimedia call.