Humza Yousaf has said the SNP would welcome a "conclusion" to Operation Branchform, but that it is for Police Scotland "to take as much time as they require in order to investigate thoroughly."

The First Minister was speaking to the BBC ahead of the arrest of Peter Murrell, the party’s former chief executive and husband of former first minister, Nicola Sturgeon.

As well as quizzing Mr Murrell for several hours on April 5 last year, officers searched and removed material from the house he shares with Ms Sturgeon and from the SNP’s HQ in Edinburgh.

The Herald:

A luxury campervan, parked in the driveway of the Fife home of Mr Murrell’s elderly mother was also seized.

READ MORE: Yousaf: 'SNP would like to see a conclusion to Operation Branchform'

Police Scotland’s investigation was launched in July 2021 after a number of complaints that £660,000 raised by the party explicitly for a second independence referendum campaign was spent on other items.

Colin Beattie, the party’s former treasurer, and Ms Sturgeon were also subsequently arrested.

All three were released pending further inquiries.

In a post on social media, Ms Sturgeon insisted that she was “innocent of any wrongdoing”

The Herald: Peter Murrell made two loans of £7500 to the party in 2018

Asked if he was frustrated over the length of time being taken by the inquiry, Mr Yousaf told the BBC: “Well, I think people will realise that all of us in the SNP would like to see a conclusion to Operation Branchform.

“I think that’s stating the obvious but, of course, it’s up to Police Scotland to determine how long that takes and for them to have the space and time to investigate thoroughly, and I don’t intend to interfere in that.

“It’s for Police Scotland to take as much time as they require in order to investigate thoroughly.”

He later told the PA that “No-one is going to interfere in that investigation.”

He added: “Police investigations should be allowed to take place without any political interference whatsoever.”

Mr Yousaf said: “There’s always challenges, circumstances like this. That’s not what I’m focused on.”

READ MORE: Operation Branchform: 'We have always acted in interests of justice'

Mr Murrell’s arrest came a week after Mr Yousaf replaced Ms Sturgeon as First Minister.

One of those who initially complained to police was Sean Clerkin.

He told The Herald he wanted a statement from Chief Constable Jo Farrell.

“I do believe that Police Scotland is doing its very best on this investigation. I’ve believed that from day one. They were very serious about it. But it's been too quiet, too secretive,” he said.

“The chief constable has got to come forward and make a public statement on where the investigation is at and where it's going and what the timeline is. Taxpayers have paid out £1.3 million for this investigation.”

“The bottom line is that those individuals [who donated to the SNP’s Indyref fund] were promised their money would be used for one thing and one thing only," he added.

Mr Clerkin said the party  should consider refunding all those who donated.

READ MORE: Operation Branchform: What is the SNP finance probe?

Scottish Tory chair, Craig Hoy, said the investigation had been a “major hit” on Police Scotland's finances.

He said: “The fact that this investigation is still going on a year on from the arrest of Peter Murrell only confirms the seriousness of what the police are probing.

“The picture surrounding the SNP’s finances has become increasingly murky and senior SNP figures must continue to co-operate fully with this investigation. That appeared not to be the case recently when they appeared to be begging for the return of their controversial campervan.

“Operation Branchform has been a major hit on Police Scotland’s already overstretched budget. This could have been avoided if the SNP had been upfront in the first place about their financial affairs.”

A Police Scotland spokesman said: “As the investigation remains ongoing we are unable to comment.”