A former sub-postmaster has said the Post Office behaved “monstrously” after he and hundreds of others were prosecuted in the Horizon IT scandal.

Ian Warren, 76, who lives in Billingford, near Dereham, was one of thousands of operators of sub-post offices across the UK to be wrongly accused of theft, fraud and false accounting by the Post Office over a 16 years between 1999 and 2015.

The false accusations were based on information from the Post Office’s IT system, Horizon, which was installed to speed up processes in the late 1990s, but errors in the software made it appear that money was missing from sub-postmasters’ branches.

More than 700 sub-postmasters were prosecuted, but to this day just 93 have been overturned.

Eastern Daily Press: Former sub-postmaster Ian WarrenFormer sub-postmaster Ian Warren (Image: Sonya Duncan)

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Mr Warren was convicted of theft in 2008 for stealing £18,000 from his Post Office branch in Essex.

He was sentenced to nine months, suspended for two years.

“I, like thousands of others who were interviewed by the Post Office, were told we were the only ones, which was a downright lie,” Mr Warren said.

"It was hideous for them to keep from us that there were so many other people involved.

“They lied to us. Over 700 of us were prosecuted, which is an awful lot of sub-postmasters all to have gone rogue.

“It was hideously unfair because they knew there were bugs in the system.

“They really have behaved monstrously, and they’ve been caught out. But not a single Post Office employee has been held to account.

“I’ve heard from other colleagues who were appallingly treated, abused and spat at, but thankfully I didn’t have to endure that.”

Eastern Daily Press: Ian Warren Ian Warren (Image: Sonya Duncan)

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Plans for emergency legislation to fast-track the cases of hundreds of sub-postmasters prosecuted in the scandal are expected to be announced this week.

Post Office minister Kevin Hollinrake has said it is investigating ways to overturn convictions. 

He suggested that Fujitsu - the tech firm behind the Horizon software - and all others involved in the scandal will be held to account and pay towards victims' compensation.