The extraordinary story of a decade-long battle with the Post Office, fought by their own sub-postmasters. Some call it the widest miscarriage of justice in UK legal history.

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.

In this ten-part series, journalist Nick Wallis gets right to the heart of the story, as he talks to those whose lives were shattered and follows the twists and turns of a David and Goliath battle as the sub-postmasters tried to fight back.

Today we hear the part a helicopter crash played in the campaign for justice as the sub-postmasters take their case to Westminster.

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