SNP treasurer Colin Beattie has been arrested by police investigating the party’s funding and finances.
Police Scotland did not name the arrested man but said a 71-year-old suspect was detained on Tuesday.
“The man is in custody and is being questioned by Police Scotland detectives,” the force said.
“A report will be sent to the Crown Office and Procurator Fiscal Service.”
It added: “As the investigation is ongoing we are unable to comment further.”
The development comes as the SNP continues to be rocked by the scandal surrounding the party’s finances.
Earlier this month, Peter Murrell, the SNP’s former chief executive and Nicola Sturgeon’s husband, was arrested in connection with the investigation into the party’s finances.
He was later released without charge pending further investigations after an 11-hour detention.
At the same time that he was in police custody, detectives seized a £100,000 motorhome from outside the home of one of Mr Murrell’s elderly relatives.
And over the weekend, new party leader and First Minister Humza Yousaf faced calls to suspend his predecessor after a video emerged in which she appeared to tell the party’s ruling body to “be very careful” about suggesting there were any financial problems.