Nicola Sturgeon will 'definitely' campaign for the SNP before the general election, Humza Yousaf has said.

The First Minister said his predecessor would help lead events in the run-up to the UK going to the polls.

Ms Sturgeon was arrested in June last year as part of a long-running police investigation into the party's finances.

She was later released without charge and later told reporters she was "innocent of any wrongdoing".

The inquiry Operation Branchform is continuing and no report has been sent yet to the Crown Office by Police Scotland.

READ MORE: Operation Branchform: 'We have always acted in interests of justice'

Earlier this week, Sir Iain Livingstone, the former chief constable of Police Scotland, defended the inquiry amid concerns among SNP figures it was harming the party.

He said: "We have always acted in the interests of justice and the rule of law. The political circumstances are around us at all times. I know we have acted with due process.

Asked by Robert Peston on ITV if he would like to see Ms Sturgeon campaign for him at the election, Mr Yousaf said: “Oh, she definitely will — I’ve got no doubt about that.

“She’s one of the most successful politicians in Europe, she’s got a formidable track record in terms of election victories, why on earth would you not want her to be involved in that election campaign.

READ MORE:  Operation Branchform casts shadow on SNP election campaign

"So I’m certain that she absolutely will be involved in the election campaign, right throughout between now and whenever that general election is called.”

Ms Sturgeon's husband Peter Murrell, the SNP’s former chief executive, was arrested in April last year as part of Operation Branchform.

On the same day Mr Murrell was arrested, officers searched the couple’s Glasgow home and pitched a large blue tent outside the front door, which has become an enduring image of the investigation.

The SNP’s headquarters in Edinburgh was also searched.

READ MORE: Humza Yousaf ‘astonished’ as Badenoch says donor comments ‘trivia’

Colin Beattie, the former party treasurer, was also arrested and questioned. As with Ms Sturgeon, both men were released without charge pending further inquiries. 

Ms Sturgeon did not campaign during the Rutherglen & Hamilton West by-election, in which Labour defeated the SNP and has kept a relatively low profile since her arrest.

Both parties are close in the polls, which raises the possibility of Labour being the largest party in Scotland in terms of MPs because its support is concentrated in the central belt and the west of Scotland, whereas the SNP’s is spread across the country.

Elsewhere in the Peston interview, Mr Yousaf said he was “astonished” by Kemi Badenoch’s claim that the row over Frank Hester’s remarks about Diane Abbott was “trivial”.

Mr Yousaf said: “How you can describe somebody saying that a black female MP should be shot is trivial, at a time of course when unfortunately we’ve seen two MPs killed in recent years, does not make any sense to me.

“Particularly not when Kemi Badenoch, only a couple of days before that, came out and — rightly, in my opinion — called out the remarks by Frank Hester as racist.

“Look, I think as people of colour who are in senior positions of government and senior positions in public life, it doesn’t matter what your political traditions are, we’ve got two choices. We can either reach down and give other people our hand and pull them up with us, or we can pull the ladder up behind us, and I think those are the choices that we have to make.”

Mr Yousaf was criticised last weekend for saying he wants to make Scotland “Tory-free” and that he wanted Conservative values and ideas driven out of the country, as well as the party’s MPs voted out of office.

In January Prime Minster Rishi Sunak said his working assumption was that the general election would be held in the second half of this year.

Since then senior Tory figures have hinted it may take place in October.