Pallade Veneta - Scottish Nationalists rocked by arrest of former leader's husband

Peter Murrell, 58, was chief executive of the Scottish National Party (SNP) for nearly 25 years until he quit last month.

In a statement, Police Scotland said they had taken a 58-year-old man into custody for questioning over "the funding and finances of the Scottish National Party."

"Officers are also carrying out searches at a number of addresses as part of the investigation," it said, without naming the man.

Police raided the Glasgow home of Murrell and Sturgeon, erecting a crime-scene tent in the front garden, and SNP headquarters in Edinburgh.

UK media identified the arrested man as Murrell, who has long faced questions over the alleged diversion of £600,000 ($750,000) in SNP donations that were meant to support its drive for Scottish independence.

He also failed to declare a personal loan to the SNP of more than £100,000, something that could breach laws on political funding transparency.

Murrell resigned from his SNP leadership post after the party falsely denied to media that it had lost 30,000 members.

"While there was no intent to mislead, I accept that this has been the outcome," he said in resigning.

The disclosure about membership numbers came as the SNP held a bitter election to replace Sturgeon as party leader and Scotland's first minister.

After more than eight years at the helm, Sturgeon said in February that she lacked the "energy" to carry on and was stepping down.

But the police investigation into Murrell, whom she married in 2010, had been a cloud over her head.

Interviewed by Sky News on March 20, Sturgeon said she had not heard whether police wanted to interview her or her husband over the probe into the missing donations.

And denying any involvement in Murrell's interest-free loan to the SNP, she said in February: "The resources that he lent the party were resources that belonged to him."

- 'Culture of secrecy' -

There was no immediate comment about the arrest from Sturgeon, who was succeeded in late March as party leader and first minister by Humza Yousaf.

The SNP said in a statement that it "would not be appropriate to comment on any live police investigation", but that it was "cooperating fully" with the police.

Yousaf echoed the SNP line, but also distanced himself from whatever had taken place at party headquarters before he became leader.

"Clearly it's not great, and I think the sooner we can get to a conclusion in this police investigation, the better," he told Sky News.

Yousaf added: "I've never been an office bearer in the party, I've not had a role in the party finances.

"There's an opportunity with new leadership to make sure we're being transparent."

The arrest plunges the SNP deeper into crisis with Yousaf already accused of snubbing his defeated rivals for cabinet posts after the bad-tempered leadership campaign.

The campaign exposed faultlines over the party's future direction, after its demands for a fresh referendum on Scottish independence were blocked by the UK government and Supreme Court.

Recent surveys show only around 45 percent of Scots back their nation leaving the UK -- the same minority recorded in a 2014 referendum which London insists settled the matter for a generation.

Opposition parties pounced on the arrest to attack the SNP, which has also been under mounting pressure over the state of public services in Scotland.

Jackie Baillie, Scottish Labour's deputy leader, said the arrest was "deeply concerning."

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

"We need Humza Yousaf and Nicola Sturgeon to urgently state what they knew and when."

The SNP said a review into its governance "will be taken forward in the coming weeks".

R.Zaccone--PV