Police Scotland cordoned off his home while officers conducted a search.
Several police vehicles were parked and a blue police tent has been set up on the front lawn.
The officers were also seen at Gordon Lamb House, the party’s headquarters in Edinburgh’s Jackson’s Entry.
In a statement, the force said: “Today, Wednesday 5 April 2023, a 58-year-old man has been arrested as a suspect in connection with the ongoing investigation into the funding and finances of the Scottish National Party.
“The man is in custody and has been questioned by Police Scotland detectives.
“Officers are also conducting searches in multiple directions as part of the investigation.
“A report will be sent to the Crown Office and the Prosecutor’s Fiscal Service.”
The force also warned against gossip on social media, saying the matter was “active for the purposes of the Contempt of Court Act of 1981.”
Statement into the investigation into the funding and finances of the Scottish National Party: man arrested.
— Police Scotland (@PoliceScotland) April 5, 2023
A spokesman for the Crown Office and the Prosecutor’s Fiscal Service said: “COPFS will continue to work with the police on this ongoing investigation.
“It is standard practice that any case involving politicians is dealt with by prosecutors without the involvement of law enforcement officers.”
Murrell resigned as the party’s chief executive last month, a position he had held since 1999, following a dispute over membership figures.
He has been married to Ms. Sturgeon since 2010.
The investigation, known as Operation Branchform, was launched in July 2021 following a complaint by former SNP council candidate and pro-independence activist Sean Clerkin.
On February 12, the Herald on Sunday reported that police had contacted senior SNP officials as part of efforts to intensify the investigation.
Get unlimited access to The Herald with our digital package and save over 20% annually
Three days later, Mrs. Sturgeon announced that she was resigning as SNP leader and as Prime Minister.
Commenting, an SNP spokesperson said: “Clearly it would not be appropriate to comment on any live police investigation, but the SNP has been cooperating fully with this investigation and will continue to do so.
“At its meeting on Saturday, the SNP’s governing body, the NEC, agreed to a governance and transparency review, which will take place in the coming weeks.”
Scottish Labor deputy leader Jackie Baillie said: “This is a deeply concerning development and the Police Scotland investigation must be allowed to proceed without interference.
“For too long, a culture of secrecy and cover-up has been allowed to fester at the heart of the SNP.
“We urgently need Humza Yousaf and Nicola Sturgeon to state what they knew and when.”
Scottish Conservative shadow constitution secretary Donald Cameron said: “Senior SNP politicians, including Nicola Sturgeon and Humza Yousaf, must fully cooperate with the investigation into this very serious case and commit to openness and transparency.
“While there is an ongoing police investigation into the finances of the SNP, and given that a suspect has now been arrested, it is only right that due process be followed and that any potential wrongdoing be fully investigated by the police.”
Alex Salmond, the leader of the Alba party, said he could not comment on the details of the case. “I ran the SNP for a long time, so I am very saddened by what it is going through and indeed what it has become.
“But you have to remember that the cause of independence and her case has never been stronger. And that’s what I and Alba are concentrating on presenting.”
This is breaking news. More to follow…