Former sub-postmasters and politicians have called for the Post Office to face a police investigation after BBC News revealed the company knew of flaws in its Horizon IT system.
A document shows bosses and lawyers knew of issues in 2017, but kept arguing sub-postmasters were to blame.
Kevan Jones MP, who advises ministers on Post Office compensation, said “the police need to start looking at this”.
The Post Office earlier said it would be “inappropriate to comment”.
More than 900 sub-postmasters were wrongly prosecuted between 1999 and 2015 due to supposed losses flagged by the faulty Horizon IT system used in its branches.
Between 2018 and 2019, the Post Office was taken to court by 555 sub-postmasters led by Alan Bates, who successfully argued they had been wrongly prosecuted.
An internal draft report obtained by the BBC reveals the Post Office knew in 2017 that the Horizon programme could be flawed.
The draft report refers to findings being discussed with “Post Office management” and investigators at the time.
Despite that, the Post Office continued to defend the costly case with £100m of public money.
Mr Jones, a Labour MP who sits on the Horizon Compensation Advisory Board, described the Post Office’s actions in the 2018-19 court case as “an abusive use of public cash against innocent people”.
He told BBC Radio 4’s World Tonight programme: “I do now think the police need to start looking at this. More will obviously come out at the public inquiry but there’s enough out there now to start looking.
“Unless people are brought before a court of law and asked what they knew and why they took such actions, then that won’t be justice.”
The draft report, which was commissioned by the Post Office in March 2016 and compiled by accountancy firm Deloitte, was not disclosed during the court case.
Lawyers for Tim Parker, who was chair of the Post Office at the time, told the BBC the Post Office’s legal team liaised with Deloitte about the report and were responsible for handling, distributing and disclosing it.
He said the Post Office’s lawyers were also involved in the “strategy and day to day management of the litigation”.
This raises questions as to whether Post Office lawyers met their responsibilities to not mislead the court.
Mr Jones continued: “If [Post Office lawyers] knew about it, surely they’ve put themselves in a very difficult position in terms of their legal obligation to release all information to the court.”
Tory peer Lord Arbuthnot, who has been a vocal campaigner on behalf of sub-postmasters, said he believes some connected with the scandal deserve a “long spell in jail”.
He described the handling of the Alan Bates court case as “a perversion of the course of justice”.
Two former sub-postmasters who were part of that landmark case said they wanted the police to investigate the matter.
Lee Castleton – who was forced into bankruptcy after wrongly being taken to court by the Post Office – said: “It really is ‘how low can they go’ time.
“I hope it drives more impetus in the police to start to investigate wider than just scape goats.”
Janet Skinner, who was jailed for nine months in 2007, described the findings of the investigation as “gut-wrenching and sickening”.
She told BBC Radio 4: “They sent people to prison with no evidence – and the amount of evidence that’s going against them now, there needs to be this form of investigation.”
A spokesperson for Mr Parker said he had “sought, considered, and acted upon the legal advice he was given” as chair.
Fujitsu Group – which manufactured the Horizon software – said it was fully cooperating with the public inquiry and will be working with the UK government on “appropriate actions, including contribution to compensation”.
A Post Office spokesperson said in response to the BBC investigation: “We are deeply sorry for the impact of the Horizon IT Scandal on so many people’s lives and continue to pay redress to victims as swiftly as possible, with £179m paid to around 2,800 Postmasters to date.
“Alongside financial redress for victims, there must also be accountability. The best forum to achieve this is the statutory public inquiry, chaired by a judge with the power to question witnesses under oath. The next phases of the inquiry will examine the issues raised here and it would be inappropriate to comment outside of that process.”
Source: BBC