Nicola Sturgeon released without charge pending further investigation | Nicola Sturgeon

Nicola Sturgeon has been questioned “as a suspect” by detectives investigating allegations of financial misconduct by the Scottish National party.

The former first minister and SNP leader was arrested by police on Sunday morning but later released without charge, pending further inquiries, after voluntarily going to a police station.

In a statement on Sunday evening, Sturgeon said that her arrest was “both a shock and deeply distressing”. She added that: “I know beyond doubt that I am in fact innocent of any wrongdoing.”

She is the third senior figure in the SNP to be arrested as part of Operation Branchform, a Police Scotland investigation into allegations that more than £600,000 in donations for an independence campaign was misspent by the party.

Sturgeon was detained and interviewed by detectives for more than seven hours before being released from custody, travelling to an undisclosed address away from her home in Uddingston, on the outskirts of Glasgow.

A spokesperson for Sturgeon said she met the police “by arrangement”, in the knowledge she would be arrested and interviewed.

“Nicola Sturgeon has today, Sunday 11 June, by arrangement with Police Scotland, attended an interview where she was to be arrested and questioned in relation to Operation Branchform,” the spokesperson said.

“Nicola has consistently said she would co-operate with the investigation if asked and continues to do so.”

Her husband, Peter Murrell, the former chief executive of the SNP, was arrested at their home on 5 April after plainclothes officers arrived without warning. He was interviewed under caution for nearly 12 hours before being released without charge.

The police then searched their home and back garden, and also searched the SNP’s headquarters under warrant, removing boxes of documents and computers. A luxury motorhome parked outside Murrell’s mother’s house in Fife was also seized and impounded by police, as part of their investigation.

Colin Beattie MSP, then the party’s treasurer, was arrested and questioned as part of the same inquiry on 18 April and also released later without charge, pending further investigation.

Shortly before 6pm on Sunday, Police Scotland said: “A 52-year-old woman who was arrested earlier today, Sunday 11 June 2023, as a suspect in connection with the ongoing investigation into the funding and finances of the Scottish National party, has been released without charge pending further investigation.

“The woman was questioned by Police Scotland detectives after she was arrested at 10.09am. She was released from custody at 5.24pm. A report will be sent to the Crown Office and Procurator Fiscal Service.

“The matter remains active for the purposes of the Contempt of Court Act 1981 and the public are therefore advised to exercise caution if discussing it on social media.

“As the investigation is ongoing we are unable to comment further.”

Sturgeon has repeatedly insisted she knew of no wrongdoing with the SNP’s finances or its handling of more than £600,000 in donations for a future independence referendum.

Speaking to reporters at Holyrood in late April, Sturgeon also denied the police inquiry had played a part in her decision to step down in February, after eight years as SNP leader and first minister.

Describing her husband’s arrest as “traumatic” and “very difficult”, she said: “I understand the view that some people might have, that I knew this was all about to unfold and that’s why I walked away. Nothing could be further from the truth. I could not have anticipated in my worst nightmares what would have unfolded over the past few weeks.”

Speaking earlier on Sunday morning on BBC One’s Sunday with Laura Kuenssberg, Humza Yousaf, Sturgeon’s successor as first minister and SNP leader, said he could not comment on the police inquiry. “I understand why you ask the question [but] as first minister I’ve got a really important duty not to be seen to prejudice or interfere in the live police investigation,” he said.

Opposition leaders said Yousaf should now follow previous precedent by suspending Sturgeon from the party. He refused to suspend Murrell and Beattie after they were arrested, on the grounds neither had been charged or convicted.

Craig Hoy, chair of the Scottish Conservatives, said the SNP had suspended other MPs under police investigation. “The SNP continue to be engulfed in murkiness and chaos. Humza Yousaf must now show some leadership and suspend his predecessor from the SNP,” Hoy said.

Earlier this month, Scotland’s chief constable, Sir Iain Livingstone, had defended the police investigation after Sturgeon’s allies attacked the force for erecting large forensic tents outside the couple’s home after Murrell’s arrest.

Murray Foote, the SNP’s former head of communications at Holyrood, told the Daily Record in early May the use of tents was a “grotesque circus”.

Livingstone said they were erected partly to protect the couple’s privacy. He said the use of arrest and search warrants to search their home was “proportionate and necessary” and had been cleared by a judge.

“When we carry out the search we will put processes in place that are proportionate and necessary to the action being carried out, and to the inquiry and its terms, and I am satisfied that the steps we have taken are proportionate and necessary,” Livingstone told the Sunday Times.

“Stating opinion or speculation without having the knowledge and information that exists is damaging … because it infringes the rights of individuals. Operation Branchform has integrity, it is expected to have rigour. If the operation had not been pursued, I would rightly have been accused of neglect of duty.”

Senior police sources had earlier told the BBC the force had consulted the national crime agency, a UK-wide agency in charge of investigating serious and organised crime, about its investigation as a form of external peer review of its lines of inquiry.

According to one senior police source, such external reviews are generally carried out “to check on the status, strategy and direction of an investigation”. The source added: “The review checks that the lines of inquiry are correct, that nothing has been missed and that the rationale is proportionate and necessary.”