A former boss of Fujitsu has told an inquiry he feels “aggrieved” after initially believing the Horizon system was one of the company’s “major successes”.

Richard Christou said he took no responsibility for the scandal which has since been described as one of the biggest miscarriages of justice in British legal history.

Mr Christou, who was chief executive of the company between 2000 and 2004, said he always regarded the Post Office as a “satisfied customer”.

He told the probe he “knew nothing about it” while the head of International Computers Ltd (ICL), which later became Fujitsu, when addressing his accountability for the miscarriages of justice.

Another former Fujitsu boss, Duncan Tait, produced a witness statement for the inquiry in which he said ex-Post Office chief executive Paula Vennells was a “demanding customer”.

He added: “Post Office executives, including Ms Vennells, did not hesitate to escalate issues to me 365 days of the year at all times of the day and night.

“I responded rapidly every time. But they never escalated to me any issues regarding Horizon integrity.

“Indeed, I heard repeatedly that the subpostmasters’ claims regarding Horizon integrity were unfounded and that the system was working well.”

Mr Tait spoke of a time when Ms Vennells had texted him during a family dinner about the home and phone broadband (HPBB) contract.

He said: “She would forward to me complaints that she received from
HPBB customers, and contact me out of hours to report service issues to me.

“For instance, I recall receiving a text message from her during a weekend family dinner, and calling her to discuss the issue.

“Ms Vennells was a demanding customer who was very clear when an issue had arisen which she wanted fixed.”

During Mr Christou’s evidence, counsel to the inquiry Sam Stevens asked: “In terms of your accountability then, for the ICL Group and its operations, what would you say your level of accountability was?”

Mr Christou replied: “What I was responsible for was that, so far as possible, to see that the operations of ICL were carried out legally, were carried out profitably, and to report to my shareholders, Fujitsu Ltd, various issues in so far as it was necessary.

“If you mean that I was responsible for the miscarriage of justice, then I don’t accept that.

“It’s not to mitigate the miscarriage of justice, I hasten to add, I think it’s a gross miscarriage of justice.

“I really feel for the subpostmasters and the postmasters involved – but talking about accountability is a different matter.

A general view of the Post Office Horizon IT Inquiry hearing room at Aldwych House in central London
A general view of the Post Office Horizon IT Inquiry hearing room at Aldwych House in central London (Jonathan Brady/PA)

“And certainly I knew nothing about it.”

In his witness statement to the inquiry, Mr Christou added: “No further problems were raised with me in connection with Horizon during my time with Fujitsu.

“In particular, I had no knowledge of the prosecution of postmasters by (the Post Office).

“I always regarded Horizon as one of (Fujitsu’s) major successes, with (the Post Office) as a satisfied customer.”

Under questioning from Flora Page, a lawyer representing a number of subpostmasters, Mr Christou was pressed again on his accountability.

Ms Page asked: “You don’t take any responsibility?”

Mr Christou replied: “No. I’m not mitigating that there is a gross miscarriage of justice – and if you think I don’t feel for the postmasters and the subpostmasters, you’re wrong.

“I do feel – and I also feel aggrieved that what I felt was a good system has been put into such disrepute.

“But I’m not responsible for it, and I’ve said before that the real issue is the way the prosecutions were handled and the flows of information.”

More than 700 subpostmasters were prosecuted by the Post Office and handed criminal convictions between 1999 and 2015 as Fujitsu’s faulty system made it appear as though money was missing at their branches.

Hundreds of victims are awaiting compensation despite the Government announcing that those who have had convictions quashed are eligible for £600,000 payouts.