The Post Office’s legal team passed subpostmaster cases on to prosecutors in Scotland without being qualified in Scots law, the Horizon IT inquiry has heard.

Robert Daily told the probe he and other Post Office investigators were “not adequately supported” before a solicitor firm was brought in to advise in 2013.

Mr Daily also said Horizon data alone was not sufficient to proceed with a prosecution of a subpostmaster in Scotland, but it was sufficient in England and Wales.

The former Post Office investigator was involved in the criminal investigation of two wrongly convicted subpostmasters who died before their convictions were overturned.

It was recognised within (Post Office) legal services and the security team that they weren't knowledgeable about Scots Law

Newcastle subpostmaster Peter Holmes was handed a community order and a curfew and William Quarm, who had a branch in North Uist in Scotland, was sentenced to 150 hours of unpaid work following their convictions.

Giving evidence at the inquiry on Tuesday, Mr Daily said the prosecution of subpostmasters in Scotland required two corroborating pieces of evidence.

He said: “If you could only draw evidence from, for instance, Horizon data, and there was no supporting evidence then you couldn’t proceed with a case.”

Counsel to the inquiry Emma Price then asked: “Whereas in England and Wales, Horizon data alone would be sufficient, would it?”

Mr Daily replied: “I believe so.”

In his witness statement, Mr Daily said he asked for support from Scottish solicitors after becoming “concerned” that he was not receiving the same support that he was in England.

The statement read: “It was recognised within (Post Office) legal services and the security team that they weren’t knowledgeable about Scots Law.

“I was concerned that I wasn’t receiving the same legal support and I recall that I asked if Scottish solicitors could be sought to assist and advise on whether there was sufficient evidence to submit a file to COPFS (Crown Office and Procurator Fiscal Service).”

I was the only investigator and I just felt as if, at times, I would pass a case down to the criminal law team and there wasn't a full understanding of Scots law

Ms Price asked: “Do you mean that there were no Scottish qualified lawyers within the criminal team?”

Mr Daily replied: “Correct.”

Ms Price continued: “Is it right therefore that prior to managing to gain approval for BTO Solicitors to advise on Scottish cases in… 2013… the criminal law team was providing a decision on whether a case should be passed to the Crown Office and Procurator Fiscal Service without being qualified in Scottish law?”

Mr Daily said: “I believe so, yes.”

The counsel to the inquiry then asked: “Did that concern you at the time?”

Mr Daily responded: “It did concern me more when I was on my own in Scotland from about 2000 into 2008, 2009 possibly.

“I was the only investigator and I just felt as if, at times, I would pass a case down to the criminal law team and there wasn’t a full understanding of Scots law.

“I did approach the subject prior to 2013 to question if we could get anyone, but that just wasn’t forthcoming at that time – I can’t recall the dates when I did that.”

Ms Price went on: “Can you recall how long before 2013 you raised that?”

The Post Office witness said: “Possibly a couple of years, I just can’t be certain.”

Ms Price also asked: “Do you consider that Post Office investigators in Scotland were not adequately supported prior to the appointment of BTO Solicitors to advise in 2013?”

Mr Daily replied: “Yes.”

More than 700 Post Office branch managers were convicted after Fujitsu’s faulty accounting software Horizon made it look like money was missing from their shops.

The saga prompted outcry from across the country after it was dramatised in a series for ITV this month.

Hundreds of subpostmasters are awaiting compensation despite the Government announcing that those who have had convictions quashed are eligible for £600,000 compensation.