Accounting giant EY is being investigated over its audits of the Post Office in relation to the Horizon scandal from March 2015 to March 2018.
The Financial Reporting Council (FRC), the UK’s accounting regulator, said it will check whether EY met its standards “with particular reference to matters related to the Horizon IT system”.
The software developed by Fujitsu was at the heart of the Post Office scandal that saw hundreds of postmasters wrongly convicted.
EY said it takes its responsibilities “extremely seriously” and will be “fully cooperating” with the FRC.
The Post Office declined to comment.
The FRC said the recent public hearings carried out as a broader inquiry into the Horizon scandal did not cover EY’s audits of the Post Office, so will not be covered by its investigation.
One of the unanswered questions of the Post Office inquiry is where all the money wrongly taken from victims of the Horizon scandal actually went.
The FRC wants to focus specifically on the role of statutory auditors – people legally required to review the financial statements of a company – in meeting the auditing standards of that time.
The announcement comes as subpostmaster campaigners Lee Castleton, Seema Misra and Chris Head will be made OBEs at Windsor castle on Wednesday.
More than 900 sub-postmasters were prosecuted for stealing because of incorrect information from the Horizon computer system. It has been called the UK’s most widespread miscarriage of justice.
The Post Office itself took many cases to court, prosecuting 700 people between 1999 and 2015.
