A barrister who advised the Post Office to stop prosecuting branch owner-operators told a public inquiry he was “now sure” that the state-owned company “must have deceived” him because it failed to provide him with “highly relevant material”. Simon Clarke, who worked for the law firm Cartwright King when it was advising the Post Office, was being questioned on Thursday as part of the judge-led hearings looking into the Horizon IT scandal. The inquiry is examining the wrongful prosecution of hundreds of branch owner-operators who were hounded by the Post Office because of financial shortfalls in their branch accounts that turned out to be caused by IT bugs in the Horizon computer system. Clarke said in his witness statement that in hindsight: “I am now sure that POL [Post Office Ltd] must have deceived both me and CK [Cartwright King]; I say this because it is now obvious to me that highly relevant material was not provided to me either at all, or when it should have been provided. I conclude that this failure to properly inform me was a decision taken by those in a position to do [and] act as they did.” He told the inquiry he felt the Post Office had “deliberately withheld” a key document from him when he was asked in 2014 to review the case of Seema Misra, a branch operator who had been wrongly convicted in 2010 and who was seeking to overturn her conviction. Misra was sentenced to 15 months in prison for theft and was jailed on her son’s 10th birthday while eight weeks pregnant. She was among those exonerated by the court of appeal in 2021. Clarke said that when he began to review Misra’s case, he was told the Post Office’s prosecution file was not available. He told the inquiry he now believed it was “deliberately withheld” from him. “That is now my view, he said, adding: “It crystallises my view that I was misled and deceived.” He said he also felt “misled and deceived” in general. “Post Office repeated their protestations that since day dot there was nothing wrong with Horizon when clearly they knew there were issues,” he told the hearing. Clarke wrote the key legal advice for the Post Office in July 2013 that made it clear there was a problem with its past prosecutions because the state-owned company had relied on testimony from the expert witness Gareth Jenkins, who was an engineer at Fujitsu, the company that developed the IT system. The barrister concluded in his legal advice that Jenkins was an “unreliable witness” who may have breached his duties to the court by failing to disclose information he knew about bugs in the Horizon software to defendants who could have used it to challenge their convictions. Clarke said prosecutions of branch owner-operators effectively stopped after he had produced his 2013 advice and he said in his witness statement that he was now “professionally and personally proud” of that fact. By 2015, the internal view at Cartwright King was that the law firm “had been mis-instructed” by the Post Office about whether the IT system could be accessed remotely by Fujitsu staff, he said. “By this time, we were coming to the realisation that something was seriously wrong with POL’s corporate culture when dealing with Horizon-related issues whether in a criminal or civil arena,” he added. The inquiry continues.