Humza Yousaf is facing calls to suspend Nicola Sturgeon from the SNP following her arrest in connection with a police probe into party finances.
Ms Sturgeon, who resigned as first minister in February, is the third senior figure to be taken into custody by officers.
She has since been released without charge pending further investigation.
Ms Sturgeon said she knows “beyond doubt” she is innocent of any wrongdoing.
But current SNP leader Mr Yousaf has been urged by opposition politicians – and one of his own MPs – to suspend his predecessor while inquiries continue.
The Tories pointed to previous examples of the SNP suspending its own parliamentarians while investigations are conducted.
Scottish Conservative Chairman Craig Hoy said: “Nicola Sturgeon and other senior SNP figures – including Humza Yousaf – must cooperate fully with this police investigation and commit to full transparency surrounding it.
“The SNP continue to be engulfed in murkiness and chaos. Humza Yousaf must now show some leadership and suspend his predecessor from the SNP.”
A similar call was made by SNP MP Angus Brendan MacNeil.
He tweeted: “This soap-opera has gone far enough. Nicola Sturgeon suspended others from the SNP for an awful lot less.
“Time for political distance until the investigation ends either way.”
Update on investigation into Scottish National Party funding and finances.
— Police Scotland (@PoliceScotland) June 11, 2023
Police confirmed on Sunday that a 52-year-old woman had been arrested “as a suspect in connection with the ongoing investigation into the funding and finances of the Scottish National Party”.
The force said: “The woman is in custody and is being questioned by Police Scotland detectives.
“A report will be sent to the Crown Office and Procurator Fiscal Service.”
It later confirmed she was arrested at 10.09am and released at 5.24pm.
Third arrest in finance probe
A spokesperson for Ms Sturgeon said the arrest and questioning were made “by arrangement” with police.
In a statement posted on social media, the former SNP leader said she is “certain I committed no offence” and declared her intention to return to Holyrood “soon”.
“To find myself in the situation I did today when I am certain I have committed no offence is both a shock and deeply distressing,” Ms Sturgeon said.
“I know that this ongoing investigation is difficult for people, and I am grateful that so many continue to show faith in me and appreciate that I would never do anything to harm either the SNP or the country.
— Nicola Sturgeon (@NicolaSturgeon) June 11, 2023
“Obviously, given the nature of this process, I cannot go into detail.
“However, I do wish to say this, and to do so in the strongest possible terms. Innocence is not just a presumption I am entitled to in law.
“I know beyond doubt that I am in fact innocent of any wrongdoing.”
The Glasgow Southside MSP also thanked those who had sent messages of support.
Ms Sturgeon’s husband Peter Murrell, who is the party’s former chief executive, was the first senior figure to be arrested, on April 5.
He was later released without charge after police spent hours searching his home as officers stood guard outside.
Party treasurer Colin Beattie, who is also an MSP, was the next to be arrested on April 18. He too was later released without charge.
As well as the arrests, searches were carried out at a number of properties, including SNP headquarters in Edinburgh.
The investigation – dubbed Operation Branchform – began in 2021.
It was opened after allegations £600,000 raised for campaigning towards Scottish independence was diverted elsewhere.
Ms Sturgeon announced her resignation as first minister in February this year, saying it was not related to short-term pressures but because she knew in her “head and heart” the time was right to go.
Her husband stepped down as party chief executive during the leadership contest that followed.
Labour’s Shadow Scottish Secretary Ian Murray described Ms Sturgeon’s arrest as a “deeply concerning” development.
He said: “For too long, a culture of secrecy and cover-up has been allowed to fester at the heart of the SNP.”
Scottish Lib Dem leader Alex Cole-Hamilton said: “It’s fair to say that today’s events will have huge ramifications both for the SNP and the future of Scottish politics.”
An SNP spokesperson said: “The SNP have been cooperating fully with this investigation and will continue to do so however it is not appropriate to publicly address any issues while that investigation is ongoing.”