Fujitsu knew of defects in the Horizon IT system for nearly two decades and witness statements used in the prosecution of subpostmasters were edited to omit the problems, its European boss has admitted.
Fujitsu Europe Director Paul Patterson told the official inquiry into the Post Office scandal that bugs and errors in the faulty accounting system were known about “right from the very start” and by “all parties”.
And he said he had seen evidence of the editing of witness statements, which he described as “shameful” and “appalling”.
Hundreds of subpostmasters were prosecuted for theft and false accounting because of Horizon in what Rishi Sunak has described as “one of the greatest miscarriages of justice in our nation’s history”.
Their plight was highlighted in an ITV drama Mr Bates vs the Post Office, which triggered a public outcry and led the prime minister to announce plans to exonerate them.
Fujitsu is now facing demands to stump up “substantial” sums towards the mammoth £1bn compensation bill, after it admitted earlier this week that it had a “moral” duty to contribute.
Giving evidence to the official inquiry into the fiasco, Mr Patterson said that the earliest bug he was aware of was in November 1999 and the latest in May 2018.
When asked if Fujitsu knew about the existence of errors and defects at a “corporate level”, he said that “right from the very start of the deployment of this system there were bugs and errors and defects which were well known to all parties.”
He told the inquiry: “I’m surprised that that detail was not included in the witness statements given by Fujitsu staff to the Post Office - and I’ve seen some evidence of editing of witness statements by others.”
Pressed by the inquiry KC how he would describe the editing out of bugs or “data integrity problems” in witness statements, he said: “Shameful, appalling – my understanding of how our laws work in this country, (is) that all of the evidence should have been put in front of the sub-postmaster, that the Post Office was relying on to prosecute them.”
Data provided to subpostmasters about their branch during criminal proceedings was "not sufficient" to understand whether Horizon was “operating correctly at the relevant branch”, he also told the inquiry.
It was “certainly not a gold standard or any standard – it’s a very simple Excel file which tells you not very much,” he added.
His appearance came as the Post Office was ordered by the government to look into a second IT system - Capture - after the i newspaper revealed that a subpostmaster claims he was convicted of theft linked to a second IT system.
Appearing in front of MPs from the Business and Trade Committee on Tuesday, Mr Patterson acknowledged that Fujitsu “moral obligation” to contribute to the compensation for subpostmasters.
But he said the “right place to determine that” was after the official inquiry had published its findings.
The government has now been asked to look into the case of Steve Marston, a 67-year-old former subpostmaster in Heap Bridge, Greater Manchester, who claims the earlier IT system led to him being convicted of theft and false accounting offences in 1998.
Yesterday the Department for Business and Trade has asked the Post Office to establish “if there are issues with any other systems currently or previously used by Post Office”, following reports three former sub-postmasters have said the system was prone to errors and caused shortfalls when they went to balance their books.
A Post Office spokesman said: “We take very seriously the concerns that are being raised about cases from before the Horizon system was first rolled out in 1999, and we will of course assist in looking into such cases brought to our attention.”
Mr Marston said he did not steal “a penny” but pleaded guilty to avoid being sent to prison.
“They said pleading guilty was the only way to avoid going to jail,” he said. “I just thought it must be something I’m doing wrong; computers were in their infancy, you didn’t think they could be wrong.”
“They said ‘Capture doesn’t make mistakes’,” he added.
