False evidence by Post Office’s expert contradicted his own report

A senior Fujitsu engineer made a false statement to court about the flawed Post Office IT system, contradicting a report he had written days earlier.

The BBC has obtained Gareth Jenkins' 2010 statement, which helped wrongly jail pregnant postmistress Seema Misra.

It said there were "no cases" where branch accounts could be altered without postmasters' knowledge.

But he had just produced a Post Office report which proposed remotely altering data in branches to fix a bug.

Mr Jenkins, Fujitsu's former chief IT architect, is currently being investigated by the Metropolitan Police for potential perjury, the BBC understands.

At least three Post Office lawyers were told about the internal report which contradicted Mr Jenkins' statement to court, but his report was not disclosed at the trial of Mrs Misra - who had been running a branch at West Byfleet in Surrey.

The Post Office said it was "deeply sorry" for the suffering caused to victims and it "remained focused" on supporting the ongoing inquiry.

• Follow live: Ex-Post Office lawyer Jarnail Singh to give evidence

Mr Jenkins' report and an accompanying memo provide the clearest evidence yet that as early as autumn 2010 the Post Office and Fujitsu, which built the Horizon IT system, were aware of details about the software which could cast doubt on prosecutions, and were keeping them hidden.

The memo, which summarised a series of meetings about the report, said that if the bug was widely known, it could cause a "loss of confidence in the Horizon system", provide branches with "ammunition to blame Horizon for future discrepancies" and have "potential impact upon ongoing legal cases".

Seema Misra was wrongly convicted and sentenced to 15 months in prison when she was eight weeks pregnant

The Horizon bug, known internally as the "receipts/payments mismatch" issue, was causing discrepancies between the accounts postmasters saw and those on the Post Office main servers. According to the memo, it was known to be affecting 40 branches.

In his report on 29 September 2010, Gareth Jenkins suggested remotely altering data to resolve the bug.

He met other Fujitsu and Post Office representatives a few days later to discuss the possible solutions.

The memo says Mr Jenkins' proposal to remotely access sub-postmasters' accounts had raised "significant data integrity concerns", could lead to questions of "tampering" and could prompt "moral implications" of the Post Office "changing branch data without informing the branch".

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In the end, the group chose a different solution - using debt recovery or refunds to make the balances match. The memo acknowledged this could "potentially highlight to branches that Horizon can lose data".

Nine days after delivering his report, Mr Jenkins submitted his final expert witness testimony, which was used by the prosecution in Mrs Misra's trial. In the months leading up to it, he had been drafting his statement for the court, with input from Post Office lawyers.

Mr Jenkins' testimony was also later used in the prosecution of many other sub-postmasters, where details of his report on the bug were again not disclosed.

The BBC has obtained his 2010 testimony, which states there are "no cases where external systems can manipulate the branch's accounts without the users in the branch being aware and authorising the transactions".

On the same day, 8 October, internal documents show that a number of Post Office lawyers had copies of both Mr Jenkins' contradictory claims - his witness statement, and the report about the bug in which he proposed remotely altering branch data.

Hundreds of postmasters were wrongly convicted because of flaws in the Horizon system. More than 100 had convictions overturned on appeal

A member of the Post Office security team had attended the meeting that discussed Mr Jenkins' report and had emailed Rob Wilson, then head of the PO's criminal law team, expressing "concern" about the proposed solutions. He wrote that they "may have repercussions in any future prosecution cases and on the integrity of the Horizon Online system".

Attached to his email were the meeting's memo and Mr Jenkins' report.

Mr Wilson then forwarded this email - and the attachments - to Jarnail Singh and Juliet McFarlane, senior lawyers who dealt with Post Office prosecutions.

Mr Singh was specifically assigned to Seema Misra's case and was responsible for disclosure - the duty to share information that might help the opposing side's case.

In a written statement to the public inquiry into the Horizon scandal last year, he said: "I do not recall having seen this document."

But Post Office records reveal that just minutes after receiving the email in 2010, he had printed off Mr Jenkins' report.

The BBC showed Mr Jenkins' report and the meeting memo to Prof Charles McLachlan, an expert witness for Mrs Misra's defence team.

Prof McLachlan said they were "completely incompatible" with Mr Jenkins' witness statement at her trial.

"There's absolutely no question that he not only knew, but was recommending remote access at a point when his witness statement was claiming there was no remote access," he said.

Prof Charles McLachlan, an expert for Ms Misra's defence, said Mr Jenkins' report was incompatible with his statement to court

Mr Jenkins' witness statement was made in response to technical issues originally raised by Prof McLachlan.

Seema Misra said seeing the documents from 2010 made her "even more angry".

"It's all clear in black and white that the Post Office and Gareth Jenkins were not telling the truth. It hurts because they could have stopped me going to prison. Saving their egos was more important."

Paul Marshall, a barrister who represented a number of sub-postmasters including Seema Misra, said he believed disclosure of Mr Jenkins report and the meeting memo would have had a "decisive impact on Mrs Misra's prosecution", and could have resulted in her acquittal.

Mr Marshall said it was "unclear" how lawyers who knew about this issue in 2010 "could have conscientiously continued to be engaged in the prosecution of postmasters".

"That destabilises and renders unsafe every single prosecution by the Post Office for the relevant period," he added.

Experts say Mrs Misra's trial was particularly significant as it was one of a few criminal cases at that time where the reliability of the Horizon system was being challenged.

During his appearance at the Post Office inquiry in December 2023, Rob Wilson - the former head of the Post Office's criminal law team - was asked why he had not disclosed knowledge of remote access to the courts.

Barrister Paul Marshall said it was hard to see how Post Office lawyers could have continued prosecutions, given what they knew

He said he had read the meeting memo about the receipts and payments bug and discussed it with Mr Singh and Ms McFarlane, but did not "understand" that one of the solutions to the bug meant remotely accessing sub-postmasters accounts.

When asked by inquiry counsel Jason Beer why the receipts/payments bug had not been disclosed, when it had been flagged as having an impact on legal cases, he said that he had viewed the issue "as being a completely different system".

He admitted he had "made the wrong decision".

Rob Wilson declined to comment to the BBC.

Jarnail Singh is being questioned again by the Post Office inquiry on Friday. His lawyer said it would be "inappropriate" for him to comment "whilst his participation in the inquiry" was ongoing.

A lawyer for Gareth Jenkins said it would be "inappropriate" for him to comment ahead of him giving evidence to the Post Office inquiry in June.

The Post Office said that Ms McFarlane has died.

The solicitors watchdog, the Solicitors Regulation Authority, said it was investigating "a number of solicitors and law firms" who were working on behalf of the Post Office, but would not take disciplinary action until the inquiry had heard all the evidence.

Fujitsu declined to answer the BBC's specific questions but said it offered "its deepest apologies" to sub-postmasters and their families.