Former First Minister Nicola Sturgeon has been arrested in connection with the ongoing investigation into the funding and finances of the SNP.
Police confirmed a 52-year-old woman was taken into custody as a suspect and is being questioned by detectives.
It follows the arrest and subsequent release of her husband, ex-SNP chief executive Peter Murrell, in April.
A spokeswoman for Ms. Sturgeon confirmed she had attended a police interview by arrangement on Sunday.
The former SNP leader, who stood down in March, was then arrested and questioned by officers who have been investigating for the past two years what happened to more than £600,000 of donations given to the party by independence activists.
The spokeswoman said: “Nicola Sturgeon has today, Sunday 11 June, by arrangement with Police Scotland, attended an interview where she was to be arrested and questioned in relation to Operation Branchform.
Ms. Sturgeon was later released on Sunday evening.