After the introduction of a new computer system in the early 2000s, the Post Office began using its data to accuse sub-postmasters of falsifying accounts and stealing money. Many were fired and financially ruined; others were prosecuted and even put behind bars.

But many of the accused insisted that they had done nothing wrong and that they were being held accountable for computer errors they could not control.

After being contacted by a man who insisted that his pregnant wife had been jailed for a crime she didn’t commit, journalist Nick Wallis started investigating what some are already describing as the widest miscarriage of justice in UK legal history.

In this ten-part series, Nick gets right to the heart of the story, as he talks to those whose lives were ruined and follows the twists and turns of a David and Goliath courtroom battle as the sub-postmasters tried to fight back. Could they have been victims of what they saw as institutionalised corporate cruelty from the Post Office?

Presenter: Nick WallisProducer: Robert NicholsonExecutive Producer: Will YatesA Whistledown production for BBC Radio 4