Nicola Sturgeon
Police Scotland said Peter Murrell, the former party chief executive, had been arrested for a second time earlier on Thursday.
Peter Murrell, the party's former chief executive, was first arrested in April last year and was released without charge.
The ex-Scottish first minister choked up as she admitted to a public inquiry she sometimes doubted whether she wanted to be in the job.
The former first minister made her frustration with the then PM clear on WhatsApp.
Scotland's former first minister was mobbed by reporters and supporters at the party's annual gathering.
The prime minister had just cracked a lame gag about Nicola Sturgeon.
Nadine Dorries fumed, Boris Johnson lobbed a grenade, Paul Scully was snubbed and Nicola Sturgeon protested her innocence
The former first minister was quizzed by detectives as part of their investigation into the SNP's finances.
Detectives have already quizzed her husband and the party's treasurer.
Detectives have also interviewed Nicola Sturgeon's husband as part of the probe.