Nicola Sturgeon’s husband is expected to be interviewed by police as part of an escalating fraud probe into "missing" SNP donations.

It was claimed on Sunday that senior party officials, including chief executive Peter Murrell who is married to the First Minister, are set to be spoken to by detectives. There is also mounting speculation that police are set to seek warrants to obtain internal SNP financial documents.

Police confirmed last week that they will formally investigate complaints into how more than £600,000 in donations for independence-related campaigns, solicited from supporters in fundraising drives, has been used.

The SNP initially claimed that the cash had been ‘ring-fenced’. However, the party’s published accounts showed that the party had less than £100,000 in the bank at the end of 2019, raising questions about what had happened to the money, with some independence supporters making complaints to police.

Douglas Chapman, the former party treasurer, and Joanna Cherry, the prominent MP, are among the senior party members who quit internal positions after complaining of a lack of transparency.

There is now mounting pressure on Mr Murrell, with a party source telling the Scottish Mail on Sunday that he had "become an embarrassment to the party, himself and Nicola".

“In any normal organisation the chief executive would have resigned or been forced to step aside at least temporarily given the police investigation,” a party source told The Sunday Mail, which reported that officers have begun contacting former party officials.

“But this really underlines that the SNP is not a normal organisation. Power is centralised to an extraordinary extent in the hands of the First Minister and her husband.

"It is unclear whether anyone in the SNP has the power to remove Murrell from his post except for his wife."

Credit: AFP

Ms Sturgeon has previously said she has no concerns over party finances. The SNP has abandoned its claim the money raised for independence campaigns was ‘ring-fenced’, instead claiming that accounts are managed on a “cash flow basis”.

It has said the same amount of money raised for independence campaigns will eventually be spent for the purpose intended by donors, although this suggests the money may already have been spent on other things, leaving the party to raise cash from other sources to meet its obligations.

Nearly £500,000 was raised after a £1 million target was set for a referendum which the SNP said would be held by 2019, although it abandoned the fundraiser and the independence plan after a backlash from voters at the 2017 general election.

Police Scotland on Sunday refused to confirm or deny that Mr Murrell would be interviewed as part of the probe, which is being conducted by Police Scotland’s financial crimes unit.

Ms Sturgeon was also accused yesterday of attempting to “bury” the issue of the cash after reports that questions had been raised at a meeting of the SNP’s national executive committee, which she attended, more than two years ago.

“Maybe Sturgeon and Murrell were so consumed by their own sense of power and confident in the blind loyalty of SNP members that they thought they could simply bury the issue," Russell Findlay, the Tory MSP, said.

"If so, they were clearly wrong. The public need to have faith in the thoroughness of the Police Scotland investigation and decisions of the Crown Office."

An SNP spokesman said: “We will cooperate fully with the police investigation, and will make no further comment.”