Fujitsu, the private entity implicated in the Post Office scandal, has been deemed the most significant lapse in justice in the annals of the United Kingdom.

The Horizon computer accounting system was developed by the £20 billion Japanese technology corporation.

Tuesday at 11:30 GMT, Fujitsu's European chief executive, Paul Patterson, will address members of the Business and Trade select committee of parliament.

They are curious about the circumstances surrounding the prosecution of roughly one thousand Post Office branch managers for theft and fraudulent accounting which occurred as a result of vulnerabilities in the Horizon system.

It was Fujitsu's acquisition of the British company ICL in the 1990s that marked the beginning of the company's long-lasting and foundational participation in government technology efforts. ICL, which was comparable to the British version of IBM, was a blue-chip company that was entrusted by governments with the delivery of comprehensive information technology initiatives.

Following the acquisition of the company, Fujitsu was able to secure a prominent place in the process of bidding for government contracts. Fujitsu is required to respond to important requests.

In the year 1996, Fujitsu was given the contract to computerise the transactions that took place at the Post Office.

It was implemented in 1999, and reports of issues began to surface almost immediately. There were two possible explanations: either the computer system malfunctioned or sub-postmasters and postmistresses engaged in extensive fraud.

As to why did the allegations of extensive issues fail to raise concerns?

Fujitsu and the Post Office, according to some commentators, were more likely to believe that sub-postmasters and mistresses were being dishonest than to accept responsibility for the situation, despite mounting evidence to the contrary.

Paula Vennells, who oversaw the Post Office from 2012 to 2019, stated that she believed Fujitsu's assurances regarding the Horizon system were "equivalent to Fort Knox."

Fujitsu informed the Post Office that only branch managers had the ability to access or modify Horizon records; therefore, sub-postmasters could be held accountable for any errors.

It turned out that to be false. Two Fujitsu witnesses are the subject of a perjury investigation.

The Court of Appeal determined in 2019 that the Fujitsu system exhibited deficiencies. The Post Office reached a consensus to remunerate 555 mistresses and sub-postmasters.

Victims are currently eligible for three Post Office compensation schemes. In total, over 4,000 individuals have been notified of their eligibility to receive payments.

The government has allocated £1 billion in its budget for compensation. Will Fujitsu remit restitution in addition for its involvement in the scandal?

The Horizon system remains operational. The Post Office has, in fact, paid Fujitsu more than £95 million to extend the Horizon agreement through 2025's end. Substituting the system is estimated to require several years and several hundred million dollars.

Fujitsu has consistently secured additional government contracts totaling billions of dollars, including those with the Home Office, HMRC, and the Ministry of Defence, among others. This raises the issue of why Fujitsu should be entrusted with the delivery of critical services.