A method comprising: sending by a LI Mirror IMS State Function, LMISF, instructions to a Bearer Binding Intercept and Forwarding Function, BBIF, to deliver packets of IMS signalling bearers established for S8 Home Routing Access Point Names to the LI Mirror IMS State Function and receiving at the LI Mirror IMS State Function packets of the IMS signalling bearers established for S8 Home Routing Access Point Names from the Bearer Binding Intercept and Forwarding Function; and performing at the LI Mirror IMS State Function a deep packet inspection of the packets received, the deep packet inspection comprising examining Session Initiation Protocol, SIP, headers of SIP messages that carry calling party identities and/or called party identities to verify whether any of those match with intercept subject identities; and sending by the LI Mirror IMS State Function the matching SIP messages together with a correlation identifier to a law enforcement monitoring function, LEMF, through a delivery function for Intercept Related Information, IRI,, sending from the LI Mirror IMS State Function to the Bearer Binding Intercept and Forwarding Function an identity of the IMS Signalling Bearer that is being intercepted and another instruction to deliver packets of media bearers linked to the IMS Signalling Bearer to the LI Mirror IMS State Function; and receiving at the LI Mirror IMS State Function media packets of media bearers linked to the IMS Signalling Bearer from the Bearer Binding Intercept and Forwarding Function; and performing at the LI Mirror IMS State Function a deep packet inspection of the media packets and examining the IP address and the port number associated with the RTP stream of the linked media bearer, and determining an associated IMS session comparing the IP address/port number of the RTP stream with the similar information from the IMS session; and sending by the LI Mirror IMS State Function the media packets to the law enforcement monitoring function (LEMF) through a delivery function for Call Content, CC, together with the correlation number. sending by a LI Mirror IMS State Function, LMISF, instructions to a Bearer Binding Intercept and Forwarding Function, BBIF, to deliver packets of IMS signalling bearers established for S8 Home Routing Access Point Names to the LI Mirror IMS State Function and receiving at the LI Mirror IMS State Function packets of the IMS signalling bearers established for S8 Home Routing Access Point Names from the Bearer Binding Intercept and Forwarding Function; and performing at the LI Mirror IMS State Function a deep packet inspection of the packets received, the deep packet inspection comprising examining Session Initiation Protocol, SIP, headers of SIP messages that carry calling party identities and/or called party identities to verify whether any of those match with intercept subject identities; and sending by the LI Mirror IMS State Function the matching SIP messages together with a correlation identifier to a law enforcement monitoring function, LEMF, through a delivery function for Intercept Related Information, IRI,, sending from the LI Mirror IMS State Function to the Bearer Binding Intercept and Forwarding Function an identity of the IMS Signalling Bearer that is being intercepted and another instruction to deliver packets of media bearers linked to the IMS Signalling Bearer to the LI Mirror IMS State Function; and receiving at the LI Mirror IMS State Function media packets of media bearers linked to the IMS Signalling Bearer from the Bearer Binding Intercept and Forwarding Function; and performing at the LI Mirror IMS State Function a deep packet inspection of the media packets and examining the IP address and the port number associated with the RTP stream of the linked media bearer, and determining an associated IMS session comparing the IP address/port number of the RTP stream with the similar information from the IMS session; and sending by the LI Mirror IMS State Function the media packets to the law enforcement monitoring function (LEMF) through a delivery function for Call Content, CC, together with the correlation number.