The Scottish National Party's treasurer Colin Beattie has been arrested in connection with a police investigation into the party’s finances.
Police Scotland said the 71 year-old has been taken into custody and is being questioned by detectives.
The arrest of Beattie, who also serves as an MSP for Midlothian North and Musselburgh, is the second in relation to the investigation into how more than £600,000 in donations to the party earmarked for an independence referendum had been used.
Earlier this month, former party chief executive Peter Murrell was arrested and questioned for more than 11 hours before being released without charge “pending further investigation”.
Murrell is the husband of former first minister Nicola Sturgeon.
Police said a report will be submitted to the Crown Office.
Scottish Labour deputy leader Jackie Baillie said: “This is yet another deeply concerning development and the Police Scotland investigation must be allowed to proceed without interference.
“For too long, a culture of secrecy and cover-up has been allowed to fester at the heart of the SNP.
“And while the investigation spreads, the SNP is still refusing to take the basic step of suspending MSPs who are the subject of police inquiries.”
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