Two former Post Office employees who were prosecuted by the Department for Work and Pensions lost a challenge to their convictions today, with the Court of Appeal ruling that shortfalls in their branch accounts were not the result of defects with the notorious Horizon IT system.

The ruling is thought to be the first time convictions of former subpostmasters who were prosecuted by a government body other than the Post Office have been appealed.

Former subpostmasters Alan Robinson, 79, and Roger Allen, 69, were both jailed for theft within a month of each other in 2004. Robinson pleaded guilty at Bradford Crown Court that March and jailed for twelve months, while Allen pleaded guilty to theft at Norwich Crown Court the following month and sentenced to six months.

They both challenged their convictions at a hearing last month but their appeals were today dismissed. Giving the court’s ruling, Lord Justice Holroyde – sitting with Mr Justice Picken and Mrs Justice Farbey – said the court was ‘wholly unpersuaded’ that Allen’s prosecution was based solely on data from the Post Office’s Horizon accounting system.

The judge said that, even if Horizon played a role in recording the pension payments Allen was said to have stolen, ‘it does not follow that any defect in Horizon is the explanation for the shortfalls’.

‘What is required in order for this to be a “Horizon case” is that it be demonstrated that Horizon reliability was essential to the case against Mr Allen,’ Holroyde said. ‘We do not consider that this has been demonstrated by Mr Allen.’

In relation to Robinson, Holroyde said there was not ‘even the slightest hint’ that he suggested the shortfalls were the result of Horizon before he was sentenced and dismissed his appeal.

At the hearing in November, seven other former subpostmasters’ convictions were quashed by the Court of Appeal. The prosecutions of all seven were found to have been ‘an affront to the public conscience’.

Those acquittals bring the total number of former Post Office employees whose convictions have been overturned to 72, with more waiting in the wings.