Nicola Sturgeon has said she had no prior knowledge of her husband’s arrest as part of a police investigation into SNP finances.

The nationalist party was thrown into crisis on Wednesday morning as Peter Murrell was arrested by Police Scotland.

Later on Wednesday Police Scotland said Mr Murrell has been “released without charge pending further investigation”.

Police Scotland vans surrounded the couple’s home in South Lanarkshire and an investigation tent was erected in their garden.

In a statement on Wednesday evening, a spokesperson for the former SNP leader, who only stood down as Scottish First Minister last month said: “It would not be appropriate to comment on a live police investigation.

“Nicola Sturgeon had no prior knowledge of Police Scotland’s action or intentions.

“Ms Sturgeon will fully co-operate with Police Scotland if required, however at this time no such request has been made.”

The force is understood to be probing the spending of money which was earmarked for Scottish independence campaigning.

Mr Murrell, who married Ms Sturgeon in 2010, stepped down as chief executive of the SNP during the party’s recent leadership campaign, which was sparked by his wife’s resignation in February.

The arrest will be seen as another blow for Scottish nationalists in their bid to see off a Labour revival at the next election following Ms Sturgeon’s resignation.

She was replaced last week by Scotland’s former health secretary Humza Yousaf.

Police Scotland said a man, understood to be Mr Murrell, was in custody and a report was being prepared for the Crown Office and Procurator Fiscal Service.

A police tent at the couple’s home in South Lanarkshire

A force spokesman added: “A 58-year-old man has today been arrested as a suspect in connection with the ongoing investigation into the funding and finances of theScottish National Party. The man is in custody and is being questioned by Police Scotland detectives. Officers are also carrying out searches at a number of addresses as part of the investigation.

“The matter is 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.”

Police vans near the headquarters of the Scottish National Party in Edinburgh

Scottish Labour deputy leader Jackie Baillie said: “This is a deeply concerning development and the Police Scotland investigation must be allowed to proceed without interference.

“We need Humza Yousaf and Nicola Sturgeon to urgently state what they knew and when.”

The SNP released a statement saying: “Clearly it would not be appropriate to comment on any live police investigation but the SNP have been co-operating fully with this investigation and will continue to do so.

“At its meeting on Saturday, the governing body of the SNP, the NEC, agreed to a review of governance and transparency — that will be taken forward in the coming weeks.”

In 2021 police revealed they were investigating allegations that the SNP mishandled hundreds of thousands of pounds raised for independence campaigns that had not yet taken place.

Detectives last year executed a warrant in the investigation into £600,000 of “missing” funds that were raised by the party and a “substantial” number of financial documents were handed to police.

Activists accused the party of wrongly claiming that the cash would only be spent on pro-independence campaigns.

In an emotional resignation announcement in February, Ms Sturgeon said she was standing down after eight years as First Minister because the job “takes its toll on you and all around you”.

She added: “It is only possible to give absolutely everything to a job of this nature for so long.”

But she has denied the police investigation into her husband had anything to do with her decision to quit.

Responding to Mr Murrell’s resignation as SNP chief executive on 18 March, she said he had taken “responsibility for the recent issue with membership”.

She added: “He had intended to stand down when there was a new leader but I think he is right to make that announcement.”

The arrest of Mr Murrell could have a wider impact on the British political landscape as the SNP as tries to fend off a raid on key Scottish seats by Labour at the next general election.

Labour leader Sir Keir Starmer is eyeing a path to power at Westminster which runs through Scotland with pollsters predicting he could pick up 10 seats when Britain goes to the polls. At the moment Labour has only one Scottish seat but has narrowed the SNP’s poll lead to 10 points.

New leader Mr Yousaf already also faces a daunting challenge to reunite his party following his election as First Minister and reviving its administration which has come under fire over the delivery of public services and soaring NHS waiting lists. Mr Yousaf has personally faced sharp criticism for his record as health secretary.