No charging decisions will be made over potential criminal offences linked to the Post Office Horizon scandal until after a public inquiry has published its final report, police have said.
One hundred police officers from across the UK are now working on the investigation, which is focusing on potential crimes of perjury and perverting the court of justice, linked to the wrongful prosecutions of sub-postmasters and the wider presentation of the Horizon IT system as robust.
Police have said the inquiry is “unprecedented” in size, with potentially more than 3,000 victims and evidence currently including more than 1.5 million documents that have to be reviewed.
Commander Stephen Clayman said: “The sub-postmasters and their families are at the heart of this investigation and our goal is to try and secure justice for those affected by this shocking set of events, the impact of which cannot be underestimated.
“The scale of the task ahead is unprecedented and I am confident we have an excellent team in place, with the support of cutting-edge technology to strengthen our search for information and evidence in amongst the 1.5 million-plus documents obtained and which will grow.
“I do know that if you take into account Post Office criminal and private prosecutions, civil claims and contract withdrawals, there are potentially thousands of victims who we are working hard to identify and build our database so that we can ensure we reach as many affected individuals as possible.
“I cannot make promises that this will be a fast process. An investigation of this size must continue to be undertaken meticulously and methodically and will take time.
“However, I speak on behalf of our whole team when I say we will approach it with independence, precision and integrity.”
No decision will be made over potential criminal charges until the public inquiry into the scandal has published its final report, and investigators have “thoroughly reviewed” its contents.
Closing statements will be heard in the inquiry on December 16 and 17, but no firm timetable has yet been set for its final report.
Any potential criminal trials linked to the investigation are not expected to take place until 2027.
Last month the Met said four suspects had so far been identified in the investigation, and that the number was expected to rise.
Three have been interviewed under caution so far since 2021, with the most recent in September this year, and more are expected to be questioned next year.
Investigators are looking at “a significant number of people” from the Post Office, Fujitsu and in the legal profession, police said in a briefing for journalists on Tuesday.
It is understood that dozens of people have been classed as persons of interest in the investigation.
More than 900 sub postmasters were prosecuted between 1999 and 2015 after faulty Horizon accounting software made it look as though money was missing from their accounts.
Hundreds are still awaiting compensation despite the previous government saying that those who have had convictions quashed are eligible for £600,000 payouts.
The scandal is one of the most widespread miscarriages of justice in British legal history.
A Post Office spokesperson said: “Post Office has co-operated fully and openly with the Metropolitan Police since early 2020 to provide whatever information it needs for its investigations.
“This has included wide-ranging requests for large volumes of data, all of which we have agreed to. This is in addition to disclosing almost 500,000 documents to the Horizon IT Inquiry.
We will continue to co-operate with the Metropolitan Police as they undertake their investigations.”
Chairwoman of the Association of Police and Crime Commissioners, Emily Spurrell, said: “The severe and enduring impact on sub-postmasters has become increasingly clear as events have unfolded and the stories have emerged of some of those wrongfully prosecuted and convicted.
“Victims of the Horizon IT scandal exist in every part of the UK, innocent people whose lives have been ruined over a quarter of a century.
“Those who found themselves caught up in this through no fault of their own deserve justice and, as what is likely to be a lengthy police investigation scales up, they are entitled to be fully supported through it.”
She encouraged anyone affected to contact their local PCC for help accessing support services.
A portal has been set up where those with information can send details and documents to investigators at https://mipp.police.uk/operation/01MPS23V49-PO1.
