The firm which audits the SNP’s accounts has resigned, it has emerged.
Accountancy firm Johnston Carmichael informed the party that it took the decision after reviewing its client portfolio.
Earlier this week, former chief executive Peter Murrell, who is Nicola Sturgeon’s husband, was arrested on Wednesday morning by police investigating the SNP’s finances.
He was later released without charge pending further investigation.
An SNP spokesman said: “We can confirm that Johnston Carmichael will not be providing audit services to the SNP this year.
“The national treasurer is undertaking a tendering process for alternative provision and we have advised the Electoral Commission of that position.”
The BBC reported that Johnston Carmichael’s resignation took place before Mr Murrell’s arrest.
Johnston Carmichael had worked with the party for more than a decade.
They informed the party they had “taken the decision to resign following a review of our client portfolio and existing resources and commitments”.
Large political parties are required to submit independently-audited accounts to the Electoral Commission each year.
The decision means the SNP now have until the first week of July to present their accounts or face possible sanctions, including an independent audit.
He has promised a review of governance and transparency with external input, which will be discussed at a meeting of the party’s national executive committee later this month.
As Mr Murrell was arrested, a large number of police were seen entering he and Ms Sturgeon’s house in Glasgow as well as the SNP’s offices in Edinburgh.
A spokesman for Johnston Carmichael told the PA news agency: “As a regulated organisation, we adhere to our obligations on client confidentiality and do not discuss client business.”
Conservative MSP Donald Cameron said: “This resignation only raises further questions about the increasingly murky picture surrounding the SNP’s finances.
“Given this firm have audited the party’s accounts for so long, the SNP must be fully transparent over why they have decided to quit now.
“The extraordinary events of recent weeks leave the SNP with big questions to answer and their auditors’ resignation only adds to the growing number of issues they must address.
“The public are sick of the SNP shrouding matters relating to their finances behind a wall of secrecy and senior figures – including Humza Yousaf and Nicola Sturgeon – must be upfront about this situation.”