Award-winning broadcast journalist, Nick Wallis joins Nazir and Mark this week to discuss the largest miscarriage of justice in British legal history; the British Post Office scandal.

Between 2000 and 2014, the Post Office prosecuted 736 sub-postmasters and sub-postmistresses for false accounting and theft. Some went to prison following their conviction and many were financially ruined. The prosecutions were based on information from a recently installed computer system called Horizon. Except, the Horizon system was flawed...