The Deputy First Minister has called for the pro-union Better Together campaign to return a £500,000 donation from an oil executive.
Nicola Sturgeon told MSPs at Holyrood that the money from Ian Taylor, president and chief executive of Vitol, should be given back and that an investigation should consider allegations made about the firm’s international dealings.
“It’s not for me to run the No campaign, but I do agree it would be a wise course of action for them to hand back the money pending an internal investigation,” she said in response to a question from an SNP backbencher in Parliament.
Mr Taylor gave about half of the £1.1 million raised so far by Better Together, it emerged earlier this month.
The SNP immediately raised questions about the multinational company, following allegations about deals in Iraq and the former Yugoslavia, which are disputed by the firm.
Vitol has acknowledged making some payments to Saddam Hussein’s regime outside the scope of the UN’s oil-for-food programme but rejects claims they were anything other than surcharges demanded by the state oil company.
The firm was accused of being linked to an oil deal involving Serbian criminal Arkan, who led paramilitary forces in the former Yugoslavia in the 1990s.
But Vitol rejects any suggestion of illegal conduct and says it was not investigated by any government or authority.
Better Together has already said the donation was taken in good faith and there are no plans for it to be returned.
The campaign group describes Mr Taylor as a respected figure internationally with a long history of philanthropy and whose personal investment has revived the Harris Tweed industry in Scotland.