The British Government's official figures on the level of illegal file sharing in the UK come from questionable research commissioned by the music industry, the BBC has revealed.

The Radio 4 show More or Less - which is devoted to the "often abused but ever ubiquitous world of numbers" - decided to examine the Government's claim that 7m people in Britain are engaged in illegal file sharing.

The 7m figure comes from the Strategic Advisory Board for Intellectual Property, a Government advisory body.