Former Scottish first minister Nicola Sturgeon is still under investigation as part of a long-running police probe into SNP fundraising finances, Police Scotland’s chief constable has said.

Jo Farrell said she could not confirm when the Operation Branchform inquiry will end as it is still “ongoing”.

The probe was launched in 2021 to investigate how £666,953 of crowdfunding donations was spent by the party.

The party’s former chief executive Peter Murrell – who is Ms Sturgeon’s husband – was charged on April 18 this year in connection with the embezzlement of party funds and a report was later sent to the prosecution service.

Mr Murrell was initially arrested a year earlier as Police Scotland officers searched the couple’s home and erected a blue tent outside the property, while also carrying out searches at the SNP’s Edinburgh headquarters. He was released without charge at the time.

Ms Sturgeon and the party’s then treasurer Colin Beattie were both arrested in 2023 but were released pending further investigation.

Neither has been charged.

More than three years after its launch, the chief constable told Sky News the investigation is yet to conclude.

“That inquiry is ongoing,” she said as she refused to be drawn on when it would end.

Asked specifically if Ms Sturgeon and Mr Beattie remain under investigation, she replied: “Still ongoing.”

After her arrest, Ms Sturgeon told journalists she was certain she had “done nothing wrong”.