Undisclosed document could reveal pressure on Fujitsu expert witness in Post Office prosecution

A document not disclosed to the Post Office Horizon IT Inquiry may reveal the extent to which a Post Office lawyer influenced a prosecution expert, which resulted in a miscarriage of justice.

Details of a meeting between Post Office lawyers and an IT expert from Fujitsu in October 2010, which could contain vital information on how discredited computer evidence was used to wrongly convict a subpostmaster, have not been provided to the public inquiry into the Horizon scandal.

During an inquiry hearing, barrister Jason Beer KC described it as “significant” that the information had not been provided.

On the second day of questioning of former Post Office senior criminal lawyer Jarnail Singh, who was involved in the wrongful prosecution of a former subpostmaster, it was revealed that he had not followed the rules when using a Fujitsu tech executive as an expert witness.

In 2010, after suffering unexplained losses in her branch, subpostmaster Seema Misra was prosecuted by the Post Office for theft and sent to prison based on computer evidence. Misra, who was pregnant with her second child when she was sentenced, had her wrongful conviction overturned in April 2021 after it was proved that the Fujitsu-supplied Horizon software used in Post Office branches contained errors that could cause phantom shortfalls. Fujitsu IT executive Gareth Jenkins was the prosecution’s expert witness in the case.

• Read our report from the inquiry’s first day of questioning of Jarnail Singh •

During questioning, Singh denied treating Jenkins as an expert witness, claiming he was a witness of fact used to help provide an understanding of the Horizon system and suggesting it was not necessary to meet the stringent rules on using expert witnesses. A witness of fact verifies facts, whereas an expert witness can be asked to tell the court what their expertise leads them to believe in the case at hand.

Jenkins’ knowledge of Horizon errors was left out of his witness statement. Emails seen by the inquiry revealed that Jenkins knew of and had told the Post Office about possible problems where transactions were lost due to locking issues. Later, in 2013, a lawyer contracted by the Post Office, Simon Clarke of Cartwright King Solicitors, warned the Post Office that Jenkins should not be used again because he knew of computer errors but, in breach of his duties, had failed to reveal them during subpostmaster trials.

In emails to colleagues, which were seen by the inquiry, Singh referred to Jenkins as an expert. During questioning, Beer was attempting to ascertain why none of the rules applied to expert witnesses were applied to Jenkins.

He put to Singh that, in the case of Misra, no witness statement relied on by the Post Office from Jenkins included any of the necessary conclusions required by common law and the Criminal Procedure Rules for expert witnesses.

Singh said: “No, because [Jenkins] didn’t come in as an expert, in the sense of an expert; he was an expert who was experienced in the [Horizon] system in itself because it’s such a specialist system, and he [was] assisting the prosecution, the defence and the court in understanding how the system worked or the operation of the system. I think that’s why and how he came into advising – he came in as somebody who knew the system well.”

But the inquiry was shown emails Singh had sent to colleagues in September 2012 regarding appointing an expert witness in a different case. In one email, he wrote: “Thinking about choice of expert in this case. I have in the past instructed Gareth Jenkins of Fujitsu in the case of Misra, which [incidentally] was the only challenge on Horizon. He provided expertise in dealing with defence’s boundless enquiry into the whole system. Perhaps we need to reconsider whether to instruct him as he may be viewed too close to the system, but instruct somebody entirely independent?”

Singh was challenged by Beer that the language he used was “suggestive” of him viewing Jenkins as an expert witness.

“Does a solicitor ever instruct a witness of fact?” asked Beer. “No,” said Singh. Beer then asked whether “a solicitor instructs an expert”. Singh replied: “Yes.”

Singh referred to his inquiry witness statement as proof that Jenkins was not used as an expert witness. Beer said: “So you’re saying that because it’s in the witness statement you’re pointing to on the desk there, it can’t be the case that you treated Mr Jenkins as an expert?” Singh denied this.

Beer asked Singh whether he was just “covering” up the fact that he knew Jenkins was treated as an expert witness. Singh asked: “Why would I cover up?”  

Beer responded: “Because you know that you complied with none of the duties that you owed as a prosecutor, so you’ve rewritten history.”

“You said, ‘I didn’t treat him as an expert at all. He was a witness of fact throughout’, despite how you’ve described him in two emails and despite the fact that you attended a conference with counsel with him and chatted through his evidence,” said Beer.

Singh denied he had rewritten history in his witness statement and said: “I don’t know where you get that we chatted through his evidence.”

Beer asked him what happened in the meeting. Singh said he has no recollection, but added that there was an attendance note to that meeting. Beer replied: “No, that’s significant. We haven’t had disclosed to us an attendance note of what happened at the 2010 conference.”

Jenkins, who is currently being investigated by the Metropolitan Police for potential perjury in relation to evidence he gave in the Misra prosecution, is due to give evidence at the public inquiry. His appearance has been postponed twice, most recently in November. In July, a hearing featuring Jenkins in relation to phase three of the public inquiry was also postponed, after “significant” evidence included in thousands of documents was disclosed just hours before he was set to be questioned by inquiry lawyers for the first time.

The Post Office was determined to keep information about problems with Horizon away from subpostmasters. It feared, in the words of Singh, that subpostmasters with unexplained shortfalls would jump on the “Horizon bashing bandwagon”. Successful prosecutions of subpostmasters claiming Horizon errors were responsible for cash shortfalls were seen as a good way of deterring further challenges.

Between 2000 and 2003, more than 900 subpostmasters were prosecuted. To date, close to 100 former subpostmasters have had convictions that were based on evidence from Horizon overturned.

In May, the inquiry heard that in 2012, Singh made celebratory comments to colleagues in an email following the successful prosecution of Misra, who was sent to prison after being found guilty of theft when unexplained accounting shortfalls appeared in her branch, despite there being no evidence against her.

In the early days of Horizon, which was rolled out to branches in 2000, the Post Office failed in a legal battle with a subpostmaster when an expert’s witness statement undermined the Post Office’s case that the computer system was robust. In 2003, the Post Office unsuccessfully tried to convince an independent expert IT witness that he was wrong when his report put its case against a subpostmaster in doubt.

During a recent hearing in the public inquiry, it was revealed that the Post Office tried to influence an independent IT witness to convince him to change his views. In his 2003 expert witness statement, Jason Coyne, then of Best Practice Group, described the Post Office’s opinion that almost all accounting errors in computer systems were caused by user error as “quite delusional”.

Coyne was appointed as a joint expert witness for both the Post Office and the defendant Julie Wolstenholme, who was subpostmaster at the Post Office branch in Cleveleys, Lancashire. In 2001, the Post Office was suing Wolstenholme for the return of equipment used in the branch after her contract was terminated, but she said her employment was terminated unlawfully in a counterclaim which raised questions about the reliability of the Horizon computer system used in branches. The Post Office dropped the case and paid a settlement to Wolstenholme.

The inquiry also recently heard that a Post Office auditor changed her story about a subpostmaster to help win a court battle. Information in a 2004 audit report that supported a subpostmaster’s case, written by former Post Office auditor Helen Rose, was omitted from a 2006 witness statement by the same person when the dispute reached the High Court. The later witness statement also included details damaging to the subpostmaster’s case, suggesting he had been drinking alcohol while the audit was being carried out, which was not in the original audit report.

The public inquiry is investigating how hundreds of former subpostmasters were prosecuted or made bankrupt after being blamed for unexplained accounting shortfalls based on evidence from the Horizon computer system used in branches. The system has since been proved to be error-prone and nearly 100 wrongful convictions have been overturned so far, including that of Seema Misra.

Computer Weekly first exposed the scandal in 2009, with the stories of seven subpostmasters (see timeline of all Computer Weekly articles about the scandal below).