Alan Bates has told the Post Office Horizon IT inquiry he was “concerned” former chief executive Paula Vennells was “not being told the full story” about investigations by forensic accountants.
The former subpostmaster and lead campaigner wrote to Ms Vennells in May 2013, expressing his surprise that she had not offered to meet, after discoveries made by investigators Second Sight.
The auditors later released a report which identified bugs that raised concerns over the reliability of Horizon data used to prosecute subpostmasters in July 2013.
Mr Bates told the inquiry on Tuesday that he did not feel confident Ms Vennells was “truly invested” in the investigation and was “concerned” this was because she was “not being told the full story”.
In his email to Ms Vennells, who led the organisation during the height of the scandal, Mr Bates wrote: “Bearing in mind what has been discovered so far, I for one am surprised that we haven’t yet met to discuss the implications.
He continued: “I have little doubt that it is now feasible to show that many of the prosecutions that the Post Office have pressed home should never have taken place.”
In his witness statement to the inquiry, Mr Bates said: “There was a concern that perhaps the information was not getting through to Ms Vennells, as I did not think her staff were feeding back to her.
“I was concerned she was not being told the full story and so I wanted to ensure that she was being accurately informed of the whole situation.
“This was, perhaps, a failure in the way that Ms Vennells handled the situation, in that I did not feel confident that she had been receiving accurate updates and was truly invested in the investigation and the subsequent events.”
After the ITV drama Mr Bates vs The Post Office, Ms Vennells was forced to return her CBE earlier this year, after more than 1.2 million people signed a petition calling for her to hand it back.
Last Wednesday, Labour MP Liam Byrne, who chairs the Commons Business and Trade Committee, said “all options are on the table” to sanction Ms Vennells over potentially misleading Parliament regarding the scandal, after leaked recordings raised questions about her previous statements to MPs.
The covert recordings, obtained by ITV and Channel 4, show Ms Vennells was told in 2013 that there had been allegations the Horizon system could be accessed remotely, something she later told a committee of MPs was not possible.
Mr Byrne said: “We are deeply concerned by the latest revelations regarding the Post Office and will be exploring options for penalising the leadership that presided over the scandal.
“All options are on the table, including the Commons exercising its powers in relation to contempt of Parliament.”
Ms Vennells said: “I continue to support and focus on co-operating with the inquiry and expect to be giving evidence in the coming months.
“I am truly sorry for the devastation caused to the subpostmasters and their families, whose lives were torn apart by being wrongly accused and wrongly prosecuted as a result of the Horizon system.
“I now intend to continue to focus on assisting the inquiry and will not make any further public comment until it has concluded.”
Ms Vennells will give evidence to the inquiry in May.