The boss of Fujitsu Europe has admitted he “doesn’t know” whether the Post Office’s Horizon computer system, at the center of the wrongful convictions of hundreds of subpostmasters, is reliable.

Paul Patterson told the inquiry into the scandal that there had been “errors and defects” in the accounting system and it was clear “that there is a level of unreliability” at Horizon.

He agreed that this would be a problem for subpostmasters currently using Horizon.

In his second appearance before the inquiry, Mr Patterson also admitted that he did not know whether Fujitsu had made an independent report on the software system.

Although he added that he would welcome a third-party investigation.

Between 1999 and 2015, hundreds of deputy postmasters and mistresses were unfairly prosecuted after Horizon made it appear that money was missing from their branches.

Fujitsu’s Horizon contract is up for renewal early next year and could be extended for a further five years.

Patterson said he was “very concerned” about what could happen if the contract is extended because of how unreliable Horizon is.

“In my experience… if you don’t keep (IT systems) up to date, I can’t determine what will or won’t happen, which is part of my nervousness about the extension,” he said.

Monday marked the start of the final week of evidence at the inquiry, more than two and a half years since it began hearing evidence in public.

Patterson said Fujitsu was committed to paying compensation to victims of the scandal, calling it a “moral obligation,” but said the company was waiting until the end of the investigation before doing so.

In a heated exchange with Sam Stein KC, who represented some of the victims of the scandal, Patterson was asked why this was the case.

“It is now accepted that Fujitsu needs to put its money to work,” Stein said.

Patterson said the company wanted to hear all the evidence in the investigation before moving forward. “These are complex issues and we need to understand all the components,” he said.

Earlier in the day, Conservative Party leader Kemi Badenoch gave evidence: As a former business secretary, the government-owned Post Office fell under her purview.

He said the broadcast of the television drama about the Post Office scandal “brought urgency” to accelerate the payment of compensation to subpostmasters.

According to Badenoch, it is necessary for the Government to “show that it is doing the right thing.”

At the inquiry into the scandal, he accepted it was “extremely disappointing” that it took the ITV drama to compound the problem.

But he said his dispute with the Treasury over the time it took to issue compensation last August was not just a case of his “posture”.

Badenoch said ITV’s four-part drama Mr Bates vs The Post Office, which aired in January, raised awareness of the issue, moving compensation from being “a perception of value for money to a matter of perception.” public”.

He insisted that the previous government was working on this issue, but admitted it was “too slow” and criticized the entire “government machinery” for slowing down compensation.

The inquiry heard how Badenoch told the Treasury he wanted to make “fixed offers” of £100,000 to all subpostmasters with a claim, and the inquiry to barrister Jason Beer KC described his mention of “ministerial management” as a threat.

He said this could be seen as “soft power” or “posturing.”

But Badenoch denied the claim, saying: “I was pointing out the direction I wanted the department to take to make it very clear.”

He said he believed speed should trump accuracy and admitted this may not have represented good value for money from a taxpayer’s point of view.

Badenoch was also questioned about her dismissal of former Post Office president Henry Staunton.

He said he was not aware of the seriousness of the concerns about him due to “basic updates” from public officials.

His evidence gave reasons for Mr Staunton’s dismissal, which included the former president attempting to close a whistleblowing investigation into his conduct, behaving in an aggressive, intimidating and disrespectful manner and misunderstanding the work of the Office of Post Office.

Staunton has previously defended himself after a report found he used derogatory language during a meeting about recruiting a board member. He has also refuted Badenoch’s claim that he was under “formal investigation” for “serious matters such as bullying”.

Earlier on Monday, Business Secretary Jonathan Reynolds said ownership of the Post Office could be handed over to its thousands of subpostmasters across the UK.

“Nothing should be ruled out for the future of Correos,” he said, adding that the future of the organization will be defined in the first half of next year.

He said the Post Office’s corporate culture was “at the root of this scandal” and that some deputy postmasters had “lost all faith in the justice system” because of it.