OPPOSITION politicians have weighed in following the arrest of former SNP chief executive Peter Murrell.

Murrell, the husband of former first minister Nicola Sturgeon, was arrested on Wednesday morning as part of Operation Branchform, the probe looking into the SNP’s finances.

We told how officers were photographed outside of the Murrell-Sturgeon residence in Uddingston, South Lanarkshire, following news of the arrest.

READ MORE: Nicola Sturgeon's husband Peter Murrell arrested in connection with SNP party funds probe

Police Scotland officers were also spotted entering SNP HQ in Edinburgh on Wednesday morning, with at least six officers conducting a search.

Following the news, both Scottish Labour and the Scottish Tories released a short statement.

Donald Cameron MSP and Tory shadow constitution secretary, said: “Senior SNP politicians, including Nicola Sturgeon and Humza Yousaf, must cooperate fully with the investigation into this very serious case and commit to openness and transparency.

“While there is an ongoing police investigation into the SNP’s finances, and given that a suspect has now been arrested, it is right that due process is followed and any potential wrongdoing investigated thoroughly by the police.”

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

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

READ MORE: Contempt of Court: What can't media report on Peter Murrell's arrest?

Scottish Labour leader Anas Sarwar later said that it was a "really serious situation" but the police should be allowed to conduct their investigation. 

He said: "I think of course there are big questions to ask of both Nicola Sturgeon and Humza Yousaf about what they knew and when, but of course the police need to be allowed to do their job.

"What I would say though is, this isn’t the biggest news story of the week - the biggest news story of the week is the fact that we have the worst ever waiting times for cancer treatment in our country, in our history.

"Scotland remains the biggest target for cancer anywhere, in terms of the biggest killer, and that should have been the focus right now.

"Instead, we have a governing party which is talking about itself to itself, mired in scandal and division, and frankly Scotland deserves better than that."

Earlier, a spokesperson for the SNP said: “Clearly it would not be appropriate to comment on any live police investigation but the SNP have been cooperating 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.”

More to follow…