Humza Yousaf: only found out about the campervan after becoming leader (pic: Terry Murden)

Senior figures in the SNP were unaware that the party had bought a £110,000 camper van to be used as an election battle bus until it was seized by police from the driveway of Nicola Sturgeon’s mother-in-law last week.

New First Minister Humza Yousaf admitted that he only became aware of it after he was elected to party’s leadership.

The latest twist in the SNP secrecy over finances follows revelations that its ruling body, the national executive committee, did not know that its auditor Johnston Carmichael had resigned.

Peter Murrell, the party’s former chief executive, stepped down amid controversy over the party’s membership figures while, his wife Nicola Sturgeon stepped down as First Minister and party leader weeks before the police raided their home in Glasgow.

Mr Murrell was arrested and later released without charge pending further enquiries. The police also searched the headquarters of the SNP in Edinburgh.

Police seized the campervan from outside the home of Mr Murrell’s mother-in-law in Dunfermline last week. It is claimed it had not been used for two years.

The investigation into the SNP’s finances concerns £600,000 in donations for the independence referendum. A £107,620 interest-free personal loan from Mr Murrell to the party in 2021 is also said to be in its scope.

An SNP MSP told The Times that the whole affair was “very odd”, adding that there had been “no mention of a camper van presumably to ferry the leader around, which then obviously wasn’t used”.

Another senior party figure said: “If it was to be used for election campaigning, what was it doing for so long outside Peter’s mum’s and not in a paint shop having livery put on the sides?”

Mr Yousaf confirmed to Sky News that police had provided him with a warrant for the items they had seized, including the German-made Niesmann and Bischoff camper van, which was taken from the home of Margaret Murrell, 92, last Wednesday.

“The police, of course, gave us a warrant for items that they’re looking to take into their possession,” he said. “I can’t go into the detail of that, but of course the police have done the responsible thing in terms of giving us — and I as leader have seen the warrant, in terms of the items they’ve confiscated, including the motor home that you referenced.”

He said he was told the motor home was an SNP asset “shortly after I became leader of the party.”

The Scottish Conservative MSP Murdo Fraser said: “These latest revelations raise very serious questions about the way the SNP is run. Humza Yousaf now has to come clean and explain what on earth has been going on in the party of government.”