THE ongoing public inquiry has revealed that the Post Office repeatedly undermined the efforts of independent investigators examining problems with the Horizon IT system.
Forensic accountant Ian Henderson said that the Post Office improperly withheld documents from Second Sight, the company hired in 2012 to investigate the accounting software.
According to Henderson, the public entity prioritised safeguarding its own reputation over aiding sub-postmasters.
During the inquiry, he also claimed that former Post Office chief, Paula Vennells, attempted to divert the investigation away from potential miscarriages of justice.
Between 1999 and 2015, the Post Office prosecuted hundreds of sub-postmasters for theft and fraud based on faulty data from the Horizon IT system. In 2012, under pressure from MPs, the Post Office commissioned Second Sight to investigate claims that Horizon was responsible for accounting discrepancies rather than criminal actions.
Despite starting their investigation, Henderson and his colleague Ron Warmington were dismissed by the Post Office in March 2015.
Henderson revealed that the Post Office obstructed their efforts by ignoring document requests and excessively delaying responses, often citing unjustified claims of legal privilege.
When Second Sight finally received documents in late October 2012, Henderson quickly realised the potential for numerous miscarriages of justice. He alleged that Vennells persistently tried to prevent them from investigating these cases.
By February 2015, Henderson believed he was dealing with a cover-up and possibly a criminal conspiracy by the Post Office. He was also worried about potential legal repercussions for alleged breaches of confidentiality and non-disclosure agreements.
Warmington said that the Post Office, possibly at the highest levels, knew the Horizon system had been causing discrepancies for years. He accused the Post Office of unsafe prosecutions, convictions, bankruptcies, and even suicides due to the improper behaviour of its prosecutors.
An interim report by the investigators, published in July 2013, identified bugs in the Horizon system that could have invalidated many convictions. Following this, the Post Office, along with Second Sight and campaigners led by former sub-postmaster Alan Bates, established a mediation scheme in August 2013, which was shut down by March 2015.
Henderson noted that some questions posed 12 months prior to the scheme's closure remained unanswered, indicating a priority on brand protection over sub-postmaster support. He found many prosecuted cases lacked evidence of personal gain, suggesting the losses were likely caused by the faulty system.
He added that the Post Office extensively vetted sub-postmasters before hiring them, making it implausible that many would suddenly turn to crime.
He also pointed out that the Post Office had a disproportionate number of staff in its PR department compared to its legal team.
Vikram Doraiswami
Andrew Quintman
Lord Jitesh Gadhia 
