Emma Simpson,Business correspondentand
Lizzie Asante,Business reporter
The oldest surviving victim of the Post Office scandal has said the King told her it was a "dreadful thing" and "should never have happened".
Betty Brown said King Charles III made the comment as she received her OBE at Windsor Castle on Tuesday.
The 93-year-old said she asked His Majesty to talk to the prime minister about ensuring those responsible for hundreds of sub-postmasters being wrongfully prosecuted would be investigated by the police and brought to justice.
She described meeting the monarch and receiving the honour as "lovely", adding she "never ever dreamt that this would happen".
"The reason that I'm here is very sad and I don't forget that. All the heart ache of the families that this has destroyed, the heart ache of children left with nothing, that still hurts, it'll always hurt," she added.
She has dedicated the honour to "all the sub postmasters that we have lost".
Mrs Brown was one of hundreds of sub-postmasters wrongly accused of stealing or false accounting between 1999 and 2015 after a faulty IT system called Horizon made it look like money was missing from branch accounts.
The scandal has been described as one of the widest miscarriages of justice in the British legal history.
The pensioner was forced out of her County Durham Post Office in 2003 - despite her late husband Oswall having paid more than £50,000 of their savings to cover non-existent shortfalls. They had run the branch together since 1985.
Mrs Brown was appointed Officer of the Order of the British Empire (OBE) for her services to justice after campaigning for sub-postmasters affected by the scandal.
She told the BBC the King was "very knowledgeable all about Horizon".
"I said to him...would you tell your prime minister and your ministers that justice has no cost...There is no cost to justice. Doesn't matter what it costs, justice must be done," she added.
The commander leading the national police inquiry, Stephen Clayman, said the size of the investigation team would need to double to meet its current timeline of submitting files for potential prosecutions by late next year or early 2028.
A government spokesperson said the scandal was "an appalling injustice" and that it was "considering requests for further funding".
Mrs Brown said she was "honoured and humbled" to be made an OBE, adding she had finally "been heard by the system" and was "pleased that the public are still learning about this".
"A lot of them think we've had compensation, we haven't had a penny compensation. We've had what they call redress, which means they've given back the money to us that they stole from us," she said.
Mrs Brown was one of the original 555 victims who took part in the landmark group legal action led by Sir Alan against the Post Office.
Her branch had been one of the most successful in the region but eventually she had to sell it at a loss.
Talking about what happened, she previously said it "absolutely destroyed my whole life".
Both Mrs Brown and Sir Alan Bates were part of the Group Litigation Order compensation scheme, and those claimants were offered the option of taking a fixed sum of £75,000 or pursuing their own settlement.
The latest data from the government indicates that more than £1.5bn has been paid out to over 12,300 claimants, across the various Post Office redress schemes.
When the first report of the official inquiry into the scandal was published in July, the Post Office said it apologised "unreservedly" for the suffering "caused to postmasters and their loved ones".
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