Scottish Conservative chairman Craig Hoy MSP is calling on First Minister Humza Yousaf to suspend his predecessor from the SNP.

He says Nicola Sturgeon and other senior SNP figures must cooperate fully with the police investigation.

“The SNP continue to be engulfed in murkiness and chaos," he adds.

"This extremely serious matter is continuing to escalate and the result is that the SNP are totally distracted at the worst possible time."

Jamie McIvor
BBC Scotland political correspondent

There had been widespread anticipation in Scottish political circles that it was possible Nicola Sturgeon would be arrested and questioned.

She is the third person to be arrested in recent weeks, following her husband and former SNP chief executive Peter Murrell, and the party’s treasurer Colin Beattie. They were spoken to for several hours by detectives and released without charge.

This is a huge development, but the question is what police will be speaking to her about.

Police say that in time a report will go to the procurator fiscal, which prosecutes crimes in Scotland.

This arrest is the moment the SNP were dreading, regardless of what the outcome of today’s investigaton might be.

Labour MP Ian Murray, the shadow secretary of state for Scotland, said the arrest was "a deeply concerning development".

"The Police Scotland investigation must be allowed to proceed without interference," he said.

"For too long, a culture of secrecy and cover-up has been allowed to fester at the heart of the SNP."

The leader of the Scottish Liberal Democrats has given his reaction to Nicola Sturgeon's arrest.

Alex Cole-Hamilton said: "Obviously we can't comment on a live police investigation and justice must be allowed to take its course.

"It's fair to say that today's events will have huge ramifications both for the SNP and the future of Scottish politics."

Nick Eardley
Chief political correspondent

Police Scotland has been looking into SNP funding for some time.

Sturgeon is the third high-profile arrest. Her husband - Peter Murrell - was previously arrested and released without charge. So was the party’s former treasury Colin Beattie.

This is a live case, so there’s a limit to what journalists can report.

But politically, there’s no doubt this is a big blow to Scotland’s governing party.

The new leader - Humza Yousaf - had been trying to move on from arrests and police probes, to talk about policy and his vision for government.

It’s inevitable he’ll now face days of questions about this arrest and what it means for the party.

Image source, PA Media

The investigation into the SNP's finances goes back two years. Here are some of the key dates:

June 2021 - SNP chief executive Peter Murrell, the husband of Nicola Sturgeon, provides a £107,000 loan the party to "assist with cashflow"

July 2021 - Police Scotland formally launches Operation Branchform, an investigation looking into the complaints about the SNP's finances.

September 2022 - The SNP's longstanding accountants Johnston Carmichael resign from their role as auditors, but the news does not emerge until seven months later.

15 February 2023 - Nicola Sturgeon unexpectedly announces she is resigning as SNP leader and first minister, saying she knows "in my head and in my heart" this is the right time to step down.

27 March 2023: Humza Yousaf wins the SNP leadership contest. The following day he is confirmed as the new first minister.

5 April 2023: Murrell is arrested at the Glasgow home he shares with Nicola Sturgeon. He is questioned under caution and later released without charge pending further investigation. Police also search the SNP's headquarters in Edinburgh and confiscate a luxury motorhome parked in the driveway of Murrell's 92-year-old mother in Fife.

18 April 2023: SNP treasurer Colin Beattie is arrested at his home in Midlothian, and later released without charge pending further investigation. The following day he resigns his position as party treasurer.

11 June 2023: Nicola Sturgeon is arrested.

Read more: The The SNP finances controversy

Earlier, Sturgeon’s successor Humza Yousaf appeared on Sunday with Laura Kuenssberg and said that he had spoken to her recently.

He said Sturgeon told him that the last few weeks have been traumatic and difficult - but she is in a good place and doing well - after the police investigation in her home and her husband’s brief arrest.

The interview with Yousaf was recorded on Friday

An SNP spokesperson said: "These issues are subject to a live police investigation.

"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."

Image source, Getty Images

Nicola Sturgeon has been arrested by police in the latest remarkable twist in the investigation into the SNP's finances.

The former first minister has been taken into custody and is being questioned by detectives at a police station.

Officers have 12 hours from the time Sturgeon was arrested before she will either be charged with a crime or released while enquiries continue.

Her arrest also means the case is now active for the purposes of the Contempt of Court Act 1981.

It means everyone has to be careful about what they say to avoid potentially prejudicing any future trial.

However, we've put together an explainer so you can read more detail about what we are able to tell you about the arrest and investigation here.

A spokesperson for Nicola Sturgeon said:

"Nicola Sturgeon has today, Sunday 11th June, by arrangement with Police Scotland, attended an interview where she was to be arrested and questioned in relation to Operation Branchform.

"Nicola has consistently said she would cooperate with the investigation if asked and continues to do so."

Image source, Getty Images

Welcome to our live coverage of Nicola Sturgeon's arrest.

Police confirmed on Sunday a 52-year-old woman was being questioned in relation to the investigation into the SNP's finances.

Read more here while we bring you the latest reaction.