A key witness giving evidence against a sub-postmaster was told by his boss at IT contractor Fujitsu that the defendant was a ‘nasty chap’, the public inquiry into the Post Office Horizon scandal heard today.

Peter Sewell, who managed the team providing data for prosecutions of sub-postmasters, emailed prosecution witness Andy Dunks ahead of the 2006 civil trial of Lee Castleton. The former Bridlington sub-postmaster was sued in the Royal Courts of Justice for £26,000 that the Post Office claimed was missing from his branch accounts.

The Post Office Inquiry today saw the email exchange between Sewell and Dunks from December 2006.

Sewell wrote: ‘See you in court then, Fetters [sic] Lane is where they used to hang people out to dry. I dont [sic] suppose that type of thing happens any more though.’

He then described Castleton as a ‘nasty chap [who] will be all out to rubbish the FJ [Fujistu] name'. Sewell told Dunks: ‘It’s up to you to maintain absolute strength and integrity no matter what the prosecution throw at you. WE will all be behind you hoping you come through unscathed. Bless you.’

Sewell giving evidence during the Post Office Inquiry

Sewell during the Post Office Inquiry today

Source: Post Office Inquiry

Despite Sewell referring to the prosecution, Castleton was the defendant in the case. He was unsuccessful and made bankrupt after being ordered to pay more than £300,000 towards Post Office’s costs. He was portrayed by Will Mellor in the ITV drama Mr Bates v The Post Office.

Dunks replied to Sewell’s email: ‘Thank you for those very kind and encouraging words. I had to pause half way through reading it to wipe away a small tear…’.

Questioned today about this email exchange, Sewell was asked by inquiry counsel Julian Blake whether he personally saw it as his role to defend Fujitsu.

‘I guess I did but not purposely,’ he replied.

Blake then asked whether it was important to defend Fujitsu in the face of questions about the integrity of its Horizon system.

Sewell responded: ‘We all protect our own companies.’

Flora Page, for some of the wrongly accused sub-postmasters, said this was effectively a ‘pep talk’ for a Post Office witness ‘egging him on’ ahead of a trial. Page added: ‘The attitude towards sub-postmasters that was encouraged in your team must have been one that [Fujitsu witnesses] carried into court whenever they gave evidence against sub-postmasters.’

Sewell said: 'I don’t believe so.'

Page: ‘You are saying "don’t worry we are all behind you". How did you form that opinion [about Castleton]?’

Sewell replied: ‘I don’t know why I wrote it. I apologise.’

The inquiry heard that staff at Fujitsu repeatedly made references to errors in the Horizon system and the possibility that these would result in accounting imbalances.

Fujitu security analyst Penny Thomas was found to have removed a statement about the integrity of Horizon from a document she was preparing, while the system’s designer Gareth Jenkins – an expert witness on behalf of the Post Office in a number of trials – expressed concern about one report which said that Horizon was working properly.

An internal email about a branch in Glasgow in 2008 stated that 35 errors were happening every week, while staff discussed another bug where the ‘end user’ (in other words the sub-postmaster trying to reconcile accounts ‘was not informed of the failure and the transaction appeared to complete successfully’.

Another audit of the Horizon system, reported internally at Fujitsu, had identified ‘certain failure scenarios’ where it was ‘possible that the Horizon counter may write an inconsistent set of messages to the local message store’. This issue, it was noted by an internal report, ‘casts a doubt over the overall integrity of the resulting transaction data’.

Hundreds of sub-postmasters were unfairly prosecuted based on Horizon data until 2015. Fewer than 100 have had their convictions overturned and last week the prime minister announced legislation to quash all remaining convictions.