In Scotland, up to 100 people could have been wrongly convicted after being accused of embezzling money.

The first minister has vowed to work with the UK government to ensure all victims wrongly accused are exonerated, and confirmed earlier this week that all criminal convictions would be overturned in Scotland.

At First Minister's Questions on Thursday, Scottish Tory leader Douglas Ross branded it a "horrendous miscarriage of justice that ruined hundreds of lives".

Follow live: Post Office investigator faces questions at inquiry

Mr Ross noted that in Scotland prosecutions were handled by the Crown Office, not the Post Office.

He said: "So can I ask the first minister, has he established if a consent motion to UK law is the fastest way to clear all victims here in Scotland, and will he confirm to parliament how he'll work with the UK government to overturn these convictions as quickly as possible?"

In response, Mr Yousaf paid tribute to Alan Bates and all the other campaigners who have sought justice over the years.

He said: "Of course, it should not have taken a TV drama for action to have to be taken."

Mr Yousaf said he had spoken to Lord Advocate Dorothy Bain and Solicitor General Ruth Charteris, and the lord advocate is willing to provide a briefing to MSPs in terms of the Crown's own handling of the issues.

The first minister said his justice secretary had written to the UK government expressing willingness to work with Westminster to overturn wrongful convictions and agreed a legislative consent motion (LCM) is likely the fastest route.

Mr Yousaf added: "But what is absolutely certain - whether you are in Scotland or any other part of the United Kingdom and have been impacted and affected by this - sub-postmasters have waited far too long for justice. They shouldn't have to wait a moment longer."

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Continuing his questioning, Mr Ross stated that the Crown Office had been made aware of problems with the Horizon system in 2013.

In response, Mr Yousaf pointed out that a public inquiry was under way and the inaccurate evidence presented by the Post Office "is at the very heart of the scandal".

He added: "In 2015, the Crown and prosecution service issued instructions to all prosecutors not to proceed with any Post Office case in which a sufficiency of evidence was dependent on evidence from the Horizon system."

This "effectively" meant there should not have been any problematic cases too heavily dependent on Horizon evidence in Scotland since 2015, the first minister said.

However, Mr Ross said the actions of the Crown Office "should trouble us greatly" and the process of clearing innocent people's names must be "accelerated" in Scotland.

After FMQs, Mr Ross said: "There are serious questions for the Crown Office to answer. It seems they were aware of concerns about the Horizon system in 2013, more than 10 years ago.

"Good people were criminalised because of an IT failure that they had nothing to do with. It is right that no stone is left unturned in seeking answers.

"The Crown Office in Scotland must be transparent.

"The lord advocate should urgently come to the Scottish parliament to be questioned about this scandal."

It was later confirmed that Dorothy Bain KC will appear before MSPs to face questions. In a statement released on Thursday, the lord advocate was said to be finalising timings with parliamentary authorities to make a statement, after which she will take questions from MSPs.