Scotland's Nicola Sturgeon released from custody after police questioning

London: Scotland's former first minister Nicola Sturgeon was released from custody Sunday after police brought her in for questioning earlier in the day as part of an investigation into her ruling party's finances.

Police Scotland, the national force, said Sunday that a 52-year-old woman was "arrested" as a suspect in the inquiry, known as Operation Branchform, and held for questioning by detectives. The BBC and a spokeswoman for Sturgeon confirmed that she was the woman who was detained.

Later, police updated the statement and said the suspect was "released without charge pending further investigation."

"As the investigation is ongoing we are unable to comment further," the statement said.

Sturgeon, who remains a member of the Scottish Parliament, described her arrest Sunday as "both a shock and deeply distressing" in a statement she posted on Twitter.

"Innocence is not just a presumption I am entitled to in law. I know beyond doubt that I am in fact innocent of any wrongdoing," she wrote.

A spokeswoman for Sturgeon told the BBC on Sunday that the former leader "has consistently said she would cooperate with the investigation if asked and continues to do so."

Police launched the inquiry over complaints that the Scottish National Party may have misused more than 600,000 British pounds ($755,000) raised by activists campaigning for Scotland's independence from the United Kingdom. The SNP, which is the largest political party in Scotland, has denied wrongdoing.

The party has "been fully cooperating with this investigation and will continue to do so," Scottish media quoted an SNP spokesperson as saying.

"However, it is not appropriate to address any issues while that investigation is ongoing," the spokesperson said.

In Scotland, police can arrest and question anyone suspected on "reasonable grounds" of committing a crime. The suspect can be held in custody for up to 12 hours - or 24, with special permission - before police must release or charge the individual.

Sturgeon's husband and the SNP's former chief executive, Peter Murrell, was taken in for questioning in April and released without charge. Police have searched the pair's home in Glasgow, as well as the party headquarters. The party's former treasurer, Colin Beattie, was also taken into custody by Police Scotland and later released.

Sturgeon was Scotland's longest-serving first minister, holding the position as head of the country's devolved government for eight years before her sudden resignation earlier this year.

When she announced she was stepping down in February, Sturgeon cited concerns about her role as a polarizing figure in a nation divided over its future. She spearheaded an ultimately unsuccessful campaign for Scottish independence, with the majority voting in a referendum in 2014 to stay in the centuries-old union with England and Wales.

Last year, the U.K. Supreme Court ruled that the Scottish Parliament lacks the power to stage a second referendum on independence without consent from the British government. The ruling dashed hopes among some in Scotland who want to leave the United Kingdom after it withdrew from the European Union in 2020.

Sturgeon's departure raised questions over the fate of the independence movement and kick-started the race for her successor among key party leaders, with Humza Yousaf assuming the role.

In April, following Murrell's arrest, Yousaf distanced himself from Sturgeon.

"There has to be more openness, more transparency around how we do things, for our members, for the confidence of the public," he said in a briefing with journalists, Britain's Guardian newspaper reported.

On Sunday, Sturgeon thanked her supporters.

"I am grateful that so many people continue to show faith in me and appreciate that I would never do anything to harm either the SNP or the country," she said.