The family of a sub-postmistress “shunned in the street” after being convicted of stealing thousands from the branch she ran hope to finally prove her innocence 27 years on.

Pat Owen was found guilty of theft from the Broad Oak Post Office in Sturry, near Canterbury, in 1998 despite denying she had anything to do with a £6,000 shortfall in its accounts.

She narrowly avoided a prison sentence, but her family say she became a shell of herself and rarely left the house before her death from heart failure five years later, aged 62.

They now hope to prove she was a victim of a second Post Office IT scandal, and say they have the evidence to prove it.

Mrs Owen’s case is one of a new wave of claims relating to the Capture computing software, which was used in Post Office branches in the 1990s before the similarly faulty Horizon system was introduced.

Hundreds of sub-postmasters were wrongly accused and convicted of stealing after Horizon software caused false shortfalls in branch accounts between 1999 and 2015.

A report last year revealed there was also a reasonable likelihood the Capture accounting system, ditched in 1999, caused similar situations.

Mrs Owen’s husband, David, and their daughters, Juliet Shardlow and Deborah Linford, kept what happened to themselves, with neither sister even telling their husbands, or their children until the scandal was exposed in the TV drama Mr Bates v The Post Office in January last year.

Their hope is now that they will finally be able to clear her name.

Speaking about the case for the first time in 27 years, Mrs Shardlow said her beloved mum “was never the same again” following her conviction and “became a hermit”.

She told KentOnline: “She used to be able to play the piano by ear, and loved spending time with her grandson.

“She went from that to not being able to go out the door, not going anywhere with my dad – she wasn't the same woman anymore.

“Mum was a formidable woman – she was a real go-getter and was really passionate about the Post Office.

“She was a force to be reckoned with and she loved the fact she was a postmistress.

“And she went from being like that to just a shadow of herself. She lost all this weight and she got very poorly.”

The conviction and subsequent struggles in Mrs Owen’s life became an unspoken secret, with Mrs Shardlow describing it as “a blackmark on the family”.

But throughout the years, they have never given up hope of seeing her exonerated – and hope a key piece of evidence could come to their aid.

Mrs Owen’s husband kept all the documents from her case safe for more than two decades, including a file summarising the findings of an IT expert who described the computer she used as having "a faulty motherboard".

It also stated that this "would have produced calculation errors and may have been responsible for the discrepancies subsequently identified by Post Office Counters' Security and Investigation team".

The computer expert was due to give evidence in Mrs Owen's defence at court as part of her trial but failed to turn up on the day. The family never found out why.

“My dad is 81 now and all he wants to see is my mother’s name cleared. It can’t be a process that takes years. It’s already been 27 years for our family,” said Mrs Shardlow.

“Personally, I believe people affected by Capture should be exonerated without the need of going through the court process as they have been for Horizon.”

The family were buoyed by the success of the hit ITV drama which shed light on the Horizon scandal.

Twenty-one Capture cases have now been submitted to the Criminal Cases Review Commission (CCRC) for review. Before Christmas, it was eight.

If the CCRC finds significant new evidence or legal arguments not previously heard before, cases can be referred back to the Court of Appeal.

The government announced in December it will be setting up a redress scheme for Capture victims, similar to Horizon.

So far about100 people who suffered after being accused of stealing from their branch while using Capture could be eligible for redress.

Solicitor Neil Hudgell, of Hudgell Solicitors, confirmed the firm now has 21 cases with the CCRC for review relating to convictions from the period Capture was used

He is encouraging more people to come forward, even if they feel they are lacking documentation or proof.

“The government has publicly stated that it accepts and understands that, due to the length of time which has passed since the Capture system was in use, there are likely to be issues over supplying evidence relating to shortfalls, suspensions, terminations, prosecutions, and convictions,” he said.

“Our message is that people shouldn’t be put off by having a lack of paperwork, and if they know or suspect that they, or family members, were affected by accounting issues between 1992 and 1999, they should come forward.

“That includes family members acting on behalf of loved ones who have since passed away.

“Our team is highly experienced in gathering evidence dating back decades, and we will support people through the process of applying to CCRC, which is the first step towards overturning convictions.

“The more people who come forward and submit to the CCRC, the stronger the picture will be in collectively strengthening appeals when they are considered.

“That goes for former sub-postmasters, but also relatives who know their loved ones ran branches at that time, and may have experienced issues.”