Nicola Sturgeon, Scotland’s Former Leader, Is Arrested in Financial Inquiry

Nicola Sturgeon, Scotland’s former first minister, was arrested on Sunday by police officers investigating the finances of the Scottish National Party, which dominates the country’s politics and which she led until her unexpected resignation in February.

The news deepens the crisis engulfing the S.N.P., which campaigns for Scottish independence, following the earlier arrests of Ms. Sturgeon’s husband, Peter Murrell, the party’s former chief executive, and then of Colin Beattie, its former treasurer.

Both men were released without being charged after questioning, but the latest development is a dramatic fall from grace for Ms. Sturgeon, a popular politician who served as Scotland’s first minister for more than eight years until she announced her resignation.

That decision took the political world by surprise and prompted a divisive race to succeed her that was ultimately won by Humza Yousaf, previously Scotland’s health secretary.

However, Mr. Yousaf’s efforts to establish himself as Scotland’s new first minister have been overshadowed by the extraordinary drama after the recent escalation of the police investigation into the S.N.P.’s finances.

In line with normal British protocol, Ms. Sturgeon was not named in a statement from Police Scotland, which said that “a 52-year-old woman” had on Sunday “been arrested as a suspect in connection with the continuing investigation into the funding and finances of the Scottish National Party,” adding that she was “in custody and is being questioned” by detectives. The BBC and other British news outlets identified the arrested woman as Ms. Sturgeon.

Police Scotland’s inquiry, code-named Operation Branchform, began in 2021 and was reported to have followed complaints about the handling of around 600,000 pounds, or nearly $750,000, in donations raised to campaign for a second vote on Scottish independence. (A first referendum on the question was held in 2014, with Scots voting by 55 percent to 45 percent against independence.)

The authorities are thought to be looking into whether money intended to fight for another vote on independence was diverted for a different purpose, and to be investigating why Mr. Murrell made a loan to the party.

Mr. Murrell, who has been married to Ms. Sturgeon since 2010, held the post of chief executive from 1999 until March, when he resigned after accepting blame for misleading statements from the party about the size of its dues-paying membership. Mr. Beattie resigned after his arrest.

After Mr. Murrell’s arrest, the British media reported that the police had seized a luxury motor home parked outside his mother’s house. Mr. Yousaf confirmed to reporters that the party had bought the vehicle — to use as a mobile office for campaigns, officials told local news outlets — but said that he only learned about the purchase after he became leader.

At the time of her resignation, Ms. Sturgeon explained her decision by saying she was exhausted and had become too polarizing a figure in Scottish politics to persuade wavering voters to support independence.

Some critics have since come to doubt that explanation but, when asked by the BBC in April if the police investigation of Mr. Murrell had prompted Ms. Sturgeon’s resignation, Mr. Yousaf replied: “No, I believe Nicola Sturgeon absolutely that she had taken the party as further forward as she possibly could.”