British Telecom is claiming billions of dollars of damages from Google in a lawsuit filed in the US which says that the Android mobile operating system infringes a number of the telecoms company's key patents. The lawsuit, filed in the state of Delaware in the US, relates to six patents which BT says are infringed by the Google Maps, Google Music, location-based advertising and Android Market products on Android. If successful, the suit could mean that Google or mobile handset makers will have to pay BT royalties on each Android handset in use and which they produce.