Nicola Sturgeon is in custody and is being questioned by Police Scotland detectives. / Photo: Reuters Archive

Former Scottish First Minister Nicola Sturgeon, who dominated politics in Scotland for years, has been arrested by police investigating the finances of the governing, pro-independence Scottish National Party.

Police Scotland said on Sunday a 52-year-old woman was detained "as a suspect in connection with the ongoing investigation into the funding and finances of the Scottish National Party."

The former leader has been ''released without charge pending further investigation," Reuters news agency reports, quoting a police statement.

UK police do not name suspects until they are charged. The British Broadcasting Corporation (BBC) and other UK media outlets have identified the arrested woman as Sturgeon. The party did not immediately comment.

Scottish police have been investigating how $745,000 (£600,000) designated for a Scottish independence campaign was spent.

'I'm innocent'

After her release by the police on Sunday, the former Scottish First Minister Nicola Sturgeon said she was innocent of any wrongdoing.

"To find myself in the situation I did today when I am certain I have committed no offence is both a shock and deeply distressing," she said in a statement on Twitter. "I know beyond doubt that I am in fact innocent of any wrongdoing."

Party treasurer Colin Beattie and former chief executive Peter Murrell were arrested previously and questioned as part of the investigation into the Scottish National Party's finances. Neither has been charged.

Murrell is Sturgeon’s husband, and police searched the couple's home in Glasgow after his arrest in April.

Power struggle

Sturgeon unexpectedly resigned in February after eight years as Scottish National Party leader and first minister of Scotland’s semi-autonomous government.

She said that it was the right time for her, her party and her country to make way for someone else.

Sturgeon left office amid divisions in the SNP and with her main goal — independence from the UK for the nation of 5.5 million people — unmet.

Scottish voters backed remaining in the UK in a 2014 referendum that was billed as a once-in-a-generation decision.

The party wants a new vote, but the UK Supreme Court has ruled that Scotland can't hold one without London's consent. The central government has refused to authorize another referendum.

Sturgeon's departure unleashed a tussle for the future of the SNP amid recriminations over the party’s declining membership and divisions about the best path towards independence.

TRT Afrika and agencies