NICOLA Sturgeon has suggested that the latest SNP MP to be investigated by police in relation to financial irregularities will remain in the party.

Dundee West MP Chris Law was detained in an investigation reported to be in connection with his Spirit of Independence referendum campaign in 2014.

Ms Sturgeon said Mr Law was "confident" that the matter would be resolved after he provided further information to the police, and, asked whether he should resign the party whip, replied: "I think we should let that process take its course.”

Natalie McGarry and Michelle Thomson, two other MPs elected in May last year, resigned the party whip after questions were raised over their financial activities and police became involved.

Ms Sturgeon said: "Michelle and Natalie took the decision to resign the whip. Chris’s position is that he is of the view, and he’s confident of the view, that when he provides the further information to the police that he’s agreed to do so then he will resolve the matter. At this stage, that process should be allowed to take its course."

Mr Law's Spirit of Independence campaign saw him raise grassroots funding to travel across Scotland in a Green Goddess fire engine, drumming up support for the Yes side.

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A Police Scotland spokeswoman said: "Police Scotland can confirm that a 46-year-old man had been detained and was released pending further inquiry."

A source close to Mr Law said: "Chris attended the police station on Wednesday morning and provided information in relation to a matter under investigation.

"He has agreed to provide the police with further information and is confident the matter will be resolved. He has not been charged with any offence."

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Earlier this week, Ms McGarry was charged in connection with fraud allegations after being interviewed by police.

The MP, who represents the Glasgow East constituency, voluntarily attended a police station in the city on Tuesday morning.

It is understood the alleged offences are linked to her involvement with the group Women For Independence, which was set up in the run-up to the 2014 Scottish referendum, and with the SNP's Glasgow Regional Association.

The amount of money allegedly involved is a five-figure sum.

Ms McGarry withdrew from the party whip in November as police continued to investigate concerns over missing donations from the prominent pro-independence group she helped set up.

As a result she was automatically suspended from the party, and currently sits as an independent MP in the House of Commons.

Asked about Ms McGarry, the First Minister said: "The charges against Natalie McGarry are serious criminal charges, they now have to be dealt with in a court of law and, you know, since that matter is now subject of criminal charges it would be completely inappropriate for me to say anything else about it."

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MP Michelle Thomson, who represents Edinburgh West, also remains suspended from the party amid an investigation into transactions involving her property firm.

All three MPs were elected in May 2015 when Nicola Sturgeon's party won all but three of the 59 Scottish seats at Westminster.

However, with Ms Thomson yet to be questioned by police and with an investigation focussed on her solicitor, SNP MPs are pushing her reinstatement. It is understood that the matter will be considered by the party's NEC at the weekend.

Ms Sturgeon said: "Michelle Thomson is not in the SNP at the moment and that remains the position.” Pushed on whether the question would be considered by the NEC at the weekend, she added: “The NEC will consider what matters it chooses to consider, but Michelle Thomson is not in the SNP."