How the fraud works

Advances in technology have made it extremely simple to clone a phone. All an aspiring fraudster needs is a radio scanner, a computer, the correct software and a connector to link the computer to the phone.

All bar the software are freely available and relatively cheap in high street electronics shops, writes Danny Penman.

When a call is made, the phone broadcasts a signal containing an electronic serial number (ESN) and its telephone number. Then, any phone can be re-programmed to fool the network into giving free access.

The fraudsters use scanners linked to computers to "listen" to the phones as they broadcast their ESNs and the phone numbers. They then re-programme or clone other phones.

Re-programmed stolen phones can be bought for pounds 10 or less and a piece of foil placed across the right connections will erase all evidence of the fraud.