Police are investigating allegations that the Scottish National party mishandled hundreds of thousands of pounds raised for independence campaigns yet to take place. Police Scotland said it had begun a criminal investigation, in consultation with prosecutors, after activists accused the party of wrongly claiming the cash would be ringfenced and only spent on pro-independence campaigns. Earlier this year three members of the SNP’s finance and audit committee and its then treasurer, the SNP MP Douglas Chapman, resigned from their posts after accusing the party of blocking their attempts to see internal “financial information”. Jo Cherry, an SNP MP close to Alex Salmond, also resigned from her party national executive post citing concerns over transparency. The party has raised nearly £667,000 since 2017 from its members and supporters for several independence campaigns that did not get fully off the ground, but admit only £57,000 was spent specifically on that campaigning. These crowdfunding initiatives were unveiled as Nicola Sturgeon, the SNP leader and first minister, sought to galvanise activists and placate hardliners following the EU referendum in 2016 by promising imminent independence campaigns and taskforces. Police Scotland had originally said it was simply assessing a complaint of “alleged financial irregularity”. On Tuesday it said it had now received seven complaints about the fate of the original donations and had begun a formal inquiry. “After assessment and consultation with the Crown Office and Procurator Fiscal Service, we will now carry out an investigation,” the force said. “Enquiries are continuing and anyone who has any information which may assist with this investigation is asked to contact police.” The party, which is run by Sturgeon’s husband, Peter Murrell, had previously stone-walled questions about how the money was accounted for and where it was held. Pressure mounted on the party following disclosures about the internal dissent by the pro-independence blogger Stuart Campbell earlier this year, which appear to be based on leaks from Sturgeon’s internal critics. A supporter of Salmond’s attacks on Sturgeon’s leadership, he published detailed allegations on his Wings over Scotland blog that there was no reference to these funds in the party’s published accounts. Colin Beattie, an SNP MSP reappointed as treasurer after Chapman’s resignation in March, acknowledged recently that nearly all the money raised for independence campaigns since 2017 had been put into general spending. In a statement following an SNP national executive meeting last month, Beattie said only £52,000 of the £666,953 raised from independence crowdfunding had been used for that purpose. He rejected demands for the money to be held in a restricted fund in the party’s accounts, but said “amounts equivalent to the sums raised” would be spent on campaigning in future “on the intended purpose”. “Of course, the SNP is the party of independence and, as such, every penny we spend – directly or indirectly – is in support of winning independence,” Beattie said. Sean Clerkin, a pro-independence activist who made the original complaints, told the Herald newspaper: “I’m very pleased the police have proceeded to a full criminal investigation so that all facts can be investigated and appropriate taken when the investigation is completed.” An SNP spokesperson said: “We will cooperate fully with any investigation. As we have made clear, all sums raised for independence campaigning will be spent on independence campaigning.”