Ex-Post Office boss Paula Vennells has broken down in tears mid-evidence as she was grilled about why she had told MPs that the Post Office had been successful in every case against subpostmasters.

The 65-year-old ordained priest admitted she “made mistakes” during her evidence to the Horizon IT inquiry on Wednesday but denied there was a conspiracy to cover up the scandal.

Ms Vennells apologised for a comment she made to MPs in June 2012, in which she said subpostmasters had been “tempted to put their hands in the till” – adding that it was an “assumption” she made.

She told the probe an email she sent to colleagues which suggested the company’s priority was to protect subpostmasters for whom the Horizon system was working, “reads badly today”.

Ms Vennells began her evidence at the Horizon IT inquiry on Wednesday by apologising for “all that subpostmasters and families have suffered”.

Asked if she was the “unluckiest CEO in the United Kingdom”, she said she had been “too trusting”.

She was given a self-incrimination warning by chairman Sir Wyn Williams at the start of her evidence, but told him: “Thank you, Sir Wyn… I plan to answer all questions.”

I have no sense that there was any conspiracy at all

After detailing a number of cases in which the Post Office had not been successful after subpostmasters blamed Horizon, counsel to the inquiry Jason Beer KC asked: “Why were you telling these parliamentarians that every prosecution involving the Horizon system had been successful and had found in favour of the Post Office?”

After a short pause in which she appeared to compose herself, Ms Vennells said: “I fully accept now that the Post Office…”

She broke off her answer to grab a tissue and held her head in her hands for a brief moment before recomposing herself.

Ms Vennells continued: “The Post Office knew that and I completely accepted.

“Personally I didn’t know that and I’m incredibly sorry that it happened to those people and to so many others.”

Of her comment that subpostmasters were being led into temptation, Ms Vennells said: “That’s a more difficult one to talk about.

“The first thing I would say on that is to apologise, because I’m very aware that that was not the case and it was an assumption I made.”

Ms Vennells explained the assumption was based on “examples of cases” and what she had been told.

She was also shown an email she sent to Jane MacLeod, former general counsel and company secretary, Mark Davies, communications director, and Alisdair Cameron, current Post Office chief financial officer.

The email read: “Our priority is to protect the business and the thousands who operated under the same rules and didn’t get into difficulties.”

She said: “I am sorry first of all because this reads badly today.”

Ms Venells added: “That wasn’t how I intended it to be read.

“I had been told, and the inquiry has heard other people say the same, that nothing had been found and so my understanding at this time was that the way the business was operating was an acceptable way, and what I was trying to say here is that we needed to make sure that the business as it was operating remained a priority for us.”

Asked about what Mr Cameron told the inquiry previously – that Ms Vennells did not believe there had been any miscarriages of justice during her tenure – Ms Vennells said: “I think that’s right.”

Mr Beer also asked if she believed there was a “conspiracy at the Post Office… to deny you information and to deny you documents and to falsely give you reassurance”.

Ms Vennells replied: “No, I don’t believe that was the case.”

She went on: “I have been disappointed, particularly more recently, listening to evidence of the inquiry where I think I remember people knew more than perhaps either they remembered at the time or I knew of at the time.

“I have no sense that there was any conspiracy at all. My deep sorrow in this is that I think that individuals, myself included, made mistakes, didn’t see things, didn’t hear things.

“I may be wrong but that wasn’t the impression that I had at the time, I have more questions now but a conspiracy feels too far-fetched.”

Asked who was responsible for organising and structuring the company, she said: “As CEO you are accountable for everything. You have experts to report to you.”

As his first major question to Ms Vennells, Mr Beer said: “Do you think you are the unluckiest CEO in the United Kingdom?”

Ms Vennells replied: “As the inquiry has heard, there was information I wasn’t given and others didn’t receive as well.

“One of my reflections of all of this – I was too trusting.

“I did probe and I did ask questions, and I’m disappointed where information wasn’t shared, and it has been a very important time for me to plug some of those gaps.”

The inquiry heard that Ms Vennells had prepared a 775-page witness statement, which took seven months to write.

Hundreds of subpostmasters were prosecuted by the business between 1999 and 2015 after Horizon, owned by Japanese company Fujitsu, made it appear as though money was missing at their branches.

The Metropolitan Police previously said they are looking at “potential fraud offences” arising out of the prosecution of subpostmasters; for example, “monies recovered as a result of prosecutions or civil actions”.

Two Fujitsu experts, who were witnesses in the trials, are being investigated for perjury and perverting the course of justice – but nobody has been arrested since the inquiry was launched in January 2020.

There are unlikely to be any criminal charges until inquiry chairman Sir Wyn completes his final report, which is expected to be published next year.

In the meantime, hundreds of subpostmasters are still awaiting compensation despite the Government announcing that those who have had convictions quashed are eligible for £600,000 payouts.