Post Office bosses should have known Horizon was faulty but "maintained the fiction that its data was always accurate" when prosecuting subpostmasters, the first tranche of a public inquiry's final report has concluded.Chairman Sir Wyn Williams said "a number of senior" people at the organisation were aware the system, known as Legacy Horizon, was capable of error up until it was changed in 2010, with a number of employees also aware the updated system, Horizon Online, also had bugs and defects.

Post Office bosses should have known Horizon was faulty but "maintained the fiction that its data was always accurate" when prosecuting subpostmasters, the first tranche of a public inquiry's final report has concluded.Chairman Sir Wyn Williams said "a number of senior" people at the organisation were aware the system, known as Legacy Horizon, was capable of error up until it was changed in 2010, with a number of employees also aware the updated system, Horizon Online, also had bugs and defects.