Police have launched a formal investigation into allegations against the SNP that more than £600,000 raised from supporters to fight an independence referendum campaign has gone missing.
Police Scotland said it had received seven complaints over the funds, amid claims they were fraudulently spent elsewhere, and had decided to launch a full inquiry after consulting with prosecutors.
The development is a major blow to Nicola Sturgeon and Peter Murrell, her husband and the SNP’s chief executive, after she denied last month that the money had "gone missing".
Although supporters have provided donations totalling more than £660,000 for a new independence campaign since 2017, the most recent party accounts revealed that the SNP had just £96,854 in the bank.
As pressure for an explanation grew, the party admitted last month that the money had not been ringfenced in its accounts despite prior assurances that it had been set aside.
Instead, it claimed it had been "earmarked" for use in a future campaign through an internal process that would "ensure that, pound for pound, that total will be spent on that campaign".
However, the disclosure suggested the cash previously donated for a referendum had been spent elsewhere, meaning money would have to be raised from other sources to meet the spending commitment.
Police Scotland has been assessing "a complaint of alleged financial irregularity" since late March to assess whether it merited a full inquiry. Last month, the force said it had received further information "which also requires to be assessed to determine if an investigation is required".
The force issued an updated statement on Tuesday. A spokesman said: "Police Scotland has now received seven complaints in relation to donations that were made to the Scottish National Party.
"After assessment and consultation with the Crown Office and Procurator Fiscal Service, we will now carry out an investigation. Enquiries are continuing, and anyone who has any information which may assist with this investigation is asked to contact police."
The investigation comes two months after Douglas Chapman, an SNP MP, resigned as the party’s treasurer in May, claiming he had not been given the information needed to carry out his duties. He was elected to the post after promising members more transparency.
Joanna Cherry QC, another prominent SNP MP, also quit the party’s ruling National Executive Committee the same month, citing issues with secrecy and scrutiny.
In March, three officials resigned in protest from the NEC’s finance and audit committee. Sources said they quit after Mr Murrell refused their request to see the party’s full accounts.
A Scottish independence activist told a court in May during a hearing considering an unrelated matter that detectives had visited him in connection with an inquiry into whether the £600,000 had gone missing.
Jackie Baillie, Scottish Labour’s deputy leader, said: "For many months, the SNP has been embroiled in internal fighting and recriminations over this most serious of matters. The truth must be known, and Police Scotland must be allowed to carry out a thorough and detailed investigation."
An SNP spokesman said: "We will co-operate fully with any investigation. As we have made clear, all sums raised for independence campaigning will be spent on independence campaigning."