BBC Panorama s63e31 Trouble at the Post Office

The Post Office has prosecuted dozens of postmasters after their computers showed that money had gone missing. Some have been jailed, but could there be other explanations for the cash shortfalls? Reporter John Sweeney meets a whistle-blower who says there were problems with the computer system. And he investigates claims that the Post Office charged some postmasters with theft even when the evidence didn't stack up.