Metropolitan Police detectives are looking at “potential fraud offences” committed during the Horizon IT scandal.
More than 700 Post Office branch managers were handed criminal convictions after faulty Fujitsu accounting software made it appear as though money was missing from their outlets.
It has been described as the most widespread miscarriage of justice in UK history and a public inquiry into it is ongoing.
Scotland Yard said on Friday evening that officers are “investigating potential fraud offences arising out of these prosecutions”, for example “monies recovered from sub-postmasters as a result of prosecutions or civil actions”.
The Met has already been looking into potential offences of perjury and perverting the course of justice in relation to investigations and prosecutions carried out by the Post Office.
Two people have been interviewed under caution but nobody has been arrested since the investigation was launched in January 2020.
After ITV aired a drama into the scandal, Mr Bates Vs The Post Office starring actor Toby Jones, 50 new potential victims have approached lawyers, it has been said.
Neil Hudgell, executive chairman of Hudgell Solicitors, who has, so far, helped 73 former subpostmasters to have convictions related to the scandal quashed, told the PA news agency: “Our clients welcome the statement from the Met.
“They want to see people properly held to account for proven wrongdoing in the prosecution and financial ruin of so many of them.
“They have complete faith in the public inquiry in the search for answers as to who knew what and when and who made the decisions on the back of that to press forward with wrongful prosecutions and civil recoveries.
“They have waited two decades for this all to unravel and will let the inquiry reach its conclusions so that the police investigation can be best informed as to what follows then.
“The drama has elevated public awareness to a whole new level. The British public and their overwhelming sympathy for the plight of these poor people has given some the strength to finally come forward.
“Those numbers increase by the day, but there are so many more out there. We had 50 up to yesterday and approaching another 20 today.”