As opposition parties accused him of laying down a smokescreen, the first minister appointed a former Whitehall mandarin to conduct an independent inquiry into whether he had misled Holyrood about whether he had formal legal advice about Scotland's EU membership and so breached the ministerial code.
His deputy, Nicola Sturgeon, had earlier appeared to offer a muted apology for the controversy which erupted on Tuesday after she revealed that her government had never asked Scotland's law officers for formal advice on whether - as Salmond has repeatedly claimed - an independent Scotland would automatically join the EU without adopting the euro.
Hours before Salmond faced a tempestuous first minister's questions at Holyrood, Sturgeon told BBC Radio Scotland: "Given the fact that previously the impression had been created that we had legal advice, that we were not prepared to reveal because somehow it didn't suit our purposes, I think was an unfortunate one."
Salmond's difficulties escalated further when it emerged that Spain's foreign minister, José García-Margallo had abandoned his government's apparent neutrality on Scottish independence by stating that an independent Scotland would need to "join the queue" to seek EU membership and gain the unanimous approval of all 27 member states.
The controversy, potentially the worst crisis Salmond has faced as first minister, arose after it emerged he had stated in a BBC1 interview with Andrew Neil earlier this year that Scotland's law officers had given him legal advice on EU membership. Salmond said: "We have, yes, in terms of the debate."
At Holyrood, Salmond faced a barrage of allegations from opposition leaders. Ruth Davidson, the Scottish Tory leader, compared him with Del Boy from Only Fools and Horses, and the former US presidents Bill Clinton and Richard Nixon.
Johann Lamont, the Scottish Labour leader, said Salmond had failed to ask his law officers basic questions about Scotland's future in EU in over five years in charge. "The reality is that the first minister will say anything to get through the moment, and then asks us to take his assertions on trust. Doesn't he realise after this week, nobody trusts him," she said.
At Westminster, Salmond was ridiculed by the leader of the Commons, Andrew Lansley, and the Labour MP for Glasgow South, Tom Harris.
Harris asked whether the UK government would start a thorough search for Salmond's missing legal advice: "We have searched everywhere for it, under the sofa, the first minister may have left it on a bus, his dog may have eaten it. We just don't know." Lansley replied: "In this context, I suspect you would be better to instigate a search for the credibility of the first minister of Scotland."
Salmond attempted to deflect their allegations by referring himself under the ministerial code. He said Sir David Bell, a former permanent secretary at the Department of Education and Skills and an assessor to the Leveson inquiry on press ethics, would investigate whether he had misled Holyrood and so broken the code.
Salmond insisted he was being misunderstood. He said: "Every major document which is published by the government is underpinned by law officers' advice. When we ask for specific advice, the law officers will give their opinion. It is absolutely clear what's being talked about is in terms of both the debate and the [Scottish government's policy] documents."
His advisers, however, struggled to contain the controversy, refusing to confirm whether it was the Scottish government's in-house lawyers or the law officers themselves - the lord advocate and solicitor general - who had independently vetted the government's policy statements on independence and the EU.
They were unable to confirm whether the Bell inquiry would consider Salmond's statements in the Andrew Neil interview, and also insisted Sturgeon had not been accepting responsibility for the confusion in her BBC interview earlier. They said she was merely referring to a misunderstanding by opposition politicians.
Catherine Stihler, the Labour MEP whose freedom of information request on Salmond's EU legal advice helped to spark the controversy, said: "This is a smokescreen by Alex Salmond. My question wasn't just about the ministerial code, it was about his abuse of power.
"I wanted to know why he went to court at the taxpayers' expense rather than answer simple questions."
guardian.co.uk © Guardian News and Media Limited 2010