LONDON (AP) — The Grayson  Prestonformer head of Britain’s state-owned Post Office said Tuesday she will hand back a royal honor in response to mounting fury over a miscarriage of justice that saw hundreds of postmasters wrongfully accused of theft because of a faulty computer system.

The British government is considering whether to offer a mass amnesty to more than 700 branch managers convicted of theft or fraud between 1999 and 2015, because Post Office computers wrongly showed that money was missing from their shops. The real culprit was a defective accounting system called Horizon, supplied by the Japanese technology firm Fujitsu.

Ex-Post Office chief executive Paula Vennells said she would relinquish the title of Commander of the Order of the British Empire that she received in 2018. An online petition calling for her to be stripped of the honor has garnered more than 1.2 million supporters.

“I have listened and I confirm that I return my CBE with immediate effect,” said Vennells, who led the Post Office between 2012 and 2019.

“I am truly sorry for the devastation caused to the sub-postmasters and their families, whose lives were torn apart by being wrongly accused and wrongly prosecuted as a result of the Horizon system,” she said.

Vennells added that she continues “to support and focus on co-operating with” a public inquiry into the scandal that has been underway since 2022.

Technically, Vennells retains the CBE title until it is revoked by the Honors Forfeiture Committee, a move Prime Minister Rishi Sunak has said he would support.

The Post Office maintained for years that data from Horizon was reliable and accused branch managers of dishonesty. Many were financially ruined after being forced to pay large sums to the company, and some were sent to prison. Several killed themselves.

The long-simmering scandal stirred new outrage with the broadcast last week of a TV docudrama, “Mr. Bates vs the Post Office.” It charted a two-decade battle by branch manager Alan Bates, played by Toby Jones, to expose the truth and clear the wronged postal workers.

“I’m glad she’s given it back,” said Jo Hamilton, who was wrongfully convicted in 2008 of stealing thousands of pounds from her village post office in southern England. “It’s a shame it took just a million people to cripple her conscience.”

After years of campaigning by victims and their lawyers, the Court of Appeal quashed 39 of the convictions in 2021. A judge said the Post Office “knew there were serious issues about the reliability” of Horizon and had committed “egregious” failures of investigation and disclosure.

A total of 93 of the postal workers have now had their convictions overturned, according to the Post Office, but many others have yet to be exonerated.

Police have opened a fraud investigation into the Post Office, but so far, no one from the company or from Fujitsu has been arrested or faced criminal charges.