Police investigating the Horizon Post Office scandal have now identified seven suspects, with more than 45 people classed as "persons of interest" though criminal trials might not get underway until 2028.
The police would not reveal the names of the seven suspects, but four of them have been interviewed, The Guardian reported. The number of formal suspects is expected to rise.
A "scaled-up" national team of officers has been in place for over six months as part of Operation Olympos - dedicated to looking at crimes related to the Horizon Post Office scandal.
The investigation, which the police described as unprecedented in size and scale, is the first to examine potential offences of perjury and perverting the course of justice by those who made “key decisions” on Post Office investigations and supporting prosecutions of branch-owner operators.
Police have said the inquiry is “unprecedented” in size, with potentially more than 3,000 victims.
Commander Stephen Clayman, Gold Command for Operation Olympos, described a "huge shift" in terms of their investigation and "significant progress".
"We've got over four million documents that are going to rise to about six million documents," he said, "but we're beginning to methodically work through those and looking at individuals who are associated with certain prosecutions."
He described a "pool of about 45 people plus" classed as "persons of interest", with that number "expected to grow".
The "wider pool" of persons of interest is made up of Post Office investigators, lawyers, and "management" across Fujitsu and the Post Office.
The team of officers will be identifying actions which could amount to criminal offences on both an individual and corporate basis.
The police, who began the Operation Olympos investigation in 2020 and by May last year had become a team of 80, have previously said that prosecutions are not expected to reach trial until 2027.
More than 900 post office operators were prosecuted by the Post Office between 1999 and 2015 because of faulty Horizon accounting software that made it look as though they had been committing fraud.
The government introduced unprecedented legislation in March 2024 to exonerate people who had been wrongly prosecuted.
Hundreds are still awaiting compensation despite the previous government saying that those who have had convictions quashed are eligible for £600,000 payouts.
Meanwhile, the chair of the public inquiry into the scandal, Sir Wyn Williams, will publish Volume 1 of his final report on July 8 and is expected to file Volume 2 later this year.