The Court of Appeal today gave judgment in the case of Hamilton and Ors v Post Office Limited. The case concerned the convictions of 42 former sub-postmasters found to have committed crimes of dishonesty against the Post Office. In 2019 Fraser J, sitting in the High Court, found that the Horizon Computer System (an accounting system used by the Post Office since approximately 1999) suffered from numerous bugs which could cause inaccuracies in branch accounts. The sub-postmasters argued that they were prosecuted and convicted on the basis of unreliable Horizon Data.
The sub-postmasters relied on two grounds of appeal. First, that it was not possible for them to have had a fair trial because information relating to the reliability of Horizon had not been disclosed. Second, that it was an "affront to the public conscience" to try them at all on the basis of a flawed accounting system. While both of these grounds are described as "abuse of process", the latter required the court to make a more significant finding about the propriety of the prosecutions and the conduct of the Post Office. The Post Office conceded the first ground early in the litigation and argued that the court should decide the case on that ground alone. In December, the sub-postmasters won the right to argue both grounds. The Post Office contested the second ground throughout.
The Court found in favour of 39 of the sub-postmasters on both grounds. Holroyde LJ and Picken and Farbey JJ held that the Post Office, as prosecutor, had a duty to properly investigate claims that Horizon was faulty and that, in assuming that the Appellants were guilty unless they could prove otherwise, had effectively reversed the burden of proof. The court concluded the failures of investigation and disclosure were "so egregious" as to make the prosecution of the 39 an affront to the conscience of the court.
The case has been described as one of the UK's most widespread miscarriages of justice and represents one of the broadest abuse of process findings in history.
Lisa Busch QC, Sam Fowles, and Olivia Davies, instructed by Hester Cavaciuti of Bindmans LLP, acted for three of the Appellants; Seema Misra, Tracy Felstead, and Janet Skinner. The court found in favour of all three appellants on both grounds. Their convictions were overturned accordingly.