The appointment of Murray Foote as the new chief executive of the SNP, months after he resigned as the party's head of communications, has caused something of a stir.

The former editor of the Daily Record has been appointed, the party said, following "a rigorous, open recruitment process" that "generated significant interest from a range of high-quality candidates". 

As well as his having resigned months earlier, Mr Foote's previous comments on the Operation Branchform investigation into the SNP have raised eyebrows.

He described the probe as a "grotesque circus" and also accused officers of “storming” SNP HQ and predicted no charges would ever be brought.

On the day of his appointment, here's a refresher on Operation Branchform.

Read More: Spin doctor who called SNP police probe 'grotesque' is party's new boss

What is Operation Branchform?

Operation Branchform was launched by Police Scotland in 2021, after concerns were raised that £666,953 raised by the SNP since 2017, ringfenced for spending on a second independence referendum, had been partly spent on other activities.

What does the investigation focus on?

As well as looking into the money raised for independence spending, Police Scotland has been investigating a loan of £107,620 made by Nicola Sturgeon's husband, Peter Murrell, to the SNP.

Mr Murrell was chief executive of the party at the time, and the loan was reported late to the electoral commission.

As it was made in the second quarter of 2021, it should have been declared to the electoral watchdog in July of that year - rules give 30 days for the body to be notified - but it was only told in August of 2022.

The Herald: Peter Murrell quit as SNP chief executive earlier this year amid a row over misleading figures

Two repayments – of £26,905 and £20,715 respectively – were made by the SNP in August and October of 2021 but as of April this year there was still money outstanding.

Police also seized a campervan worth around £110,000 from a house in Fife owned by Mr Murrell's mother. 

In July outgoing Police Scotland chief constable Sir Iain Livingstone said the investigation had widened to look at potential charges of fraud and embezzlement.

Who has been questioned?

It's now known exactly how many people have been questioned as part of the investigation, which is ongoing.

It's likely witnesses relating to both the ringfenced money for independence spending and the loan made by Mr Murrell have been questioned.

Read More: Who is Murray Foote, the SNP's new chief executive?

Who has been arrested?

On April 5 of this year Peter Murrell, who by then was no longer chief executive of the party, was arrested by Police Scotland.

He and Ms Sturgeon's private home in Glasgow was searched, as were the SNP's headquarters in Edinburgh.

He was released without charge pending further investigation.

Colin Beattie, the SNP's treasurer at the time, was arrested later that month and also released without charge.

On June 11 Ms Sturgeon was arrested, having attended a police interview by arrangement. She was also released without charge, pending further investigation.

The Herald: Nicola Sturgeon was immediately identified as the person in question when she was arrested

The investigation has also led to the resignation of key figures within the SNP - who are they and why did they resign?

It's important to note that while there has been a raft of resignations from the SNP in 2023, not all were connected to Operation Branchform.

First Minister Nicola Sturgeon stepped down as First Minister in February but has said she did not do so due to the ongoing investigation as she did not know the subsequent arrests would be coming.

Mr Murrell resigned in March, before he was arrested, after facing a vote of no confidence from the National Executive Committee.

He stepped down in the wake of the resignation of Mr Foote, who had dismissed as "drivel" a report by the Sunday Mail that membership numbers had fallen by 30,000.

The former Daily Record editor said he had been given false information by party HQ and could no longer continue in his role.

Mr Murrell said: "Responsibility for the SNP’s responses to media queries about our membership number lies with me as chief executive. While there was no intent to mislead, I accept that this has been the outcome.”

Following his arrest in April, Mr Beattie stepped down as treasurer.

He said: "I will continue to cooperate fully with Police Scotland’s enquiries and it would be inappropriate for me to comment any further on a live case.”