Alex Salmond has said he believes the Stone of Destiny on show at Edinburgh Castle is a fake, provoking a row about the authenticity of one of Scotland’s most famous cultural icons.

The first minister is convinced the original stone was hidden by the abbot of Scone 700 years ago to prevent it being looted by the English.

Salmond believes a worthless block of Perthshire sandstone was passed off as Scotland’s coronation stone when King Edward I’s army stormed Scone Abbey in 1296.

The stone on display in the crown room of Edinburgh Castle sat beneath the coronation throne in Westminster Abbey until 1996, when it was repatriated by the Tory government.

It is regarded as a powerful symbol of Scottish independence and was stolen by a gang of nationalist radicals in 1950.

“If you’re the abbot of Scone and the strongest and most ruthless king in Christendom is charging toward you in 1296 to steal Scotland’s most sacred object and probably put you and half of your cohorts to death, do you do nothing and wait until he arrives or do you hide yourself and the stone somewhere convenient in the Perthshire hillside? I think the second myself,” said Salmond.

He believes the original stone, used for the coronation of Scots kings for 500 years, may have been a fragment of meteorite. Medieval chroniclers described it as round, black and polished with carved symbols. According to legend, the Stone of Destiny was used as a pillow by the biblical patriarch Jacob when he dreamt of a ladder to heaven.

“At least one chronicler describes the stone as a shiny black object and you would think that if something was to be seen as Jacob’s pillow, Scotland’s most sacred relic, it would be very unusual to the medieval eye,” said Salmond.

“I have a hunch that the sort of thing that would go down as the Stone of Scone would be more like a meteor or something like that — something very unusual, and a lump of Perthshire sandstone, interesting and nice, doesn’t seem to be that.”

Salmond also argues that Robert the Bruce would have demanded the stone’s return if he had thought it was the genuine article.

“He didn’t do that. Why not? One explanation is that he knew it wasn’t the right stone — and the right stone was lost, mislaid or out the way and he just thought this isn’t worth the bother.”

Salmond said there was no certainty either that the stone taken from Westminster Abbey in 1950 was the stone that now lies in the crown room at Edinburgh Castle. He believes a former Glasgow councillor and stonemason, Baillie Robert Gray, made copies of the stone when he was given it by the four to repair after it broke into two pieces during the raid. He suspects Gray may have kept the real one.

“There’s no question that Bertie Gray made copies,” said Salmond. “It’s like the Loch Ness monster — it’s certainly a puzzle and a mystery which is best not definitively answered.”

The first minister’s intervention comes on the eve of the premiere of a Hollywood film, starring Robert Carlyle and Billy Boyd, about the theft of the stone from Westminster Abbey by nationalist radicals in 1950.

The SNP hopes the film, which is being billed as Braveheart II, will boost its campaign for independence. The movie is based on the book about the incident by Ian Hamilton, one of the gang who went on to become one of Scotland’s top QCs.

Hamilton, whose book The Stone of Destiny is published this week, said he was convinced that the stone in Edinburgh was the genuine article.

“Had it been a substitute for Edward to carry off it would have been produced when the king \ regained his kingdom. It wasn’t,” he said.

Geoffrey Barrow, a professor in Scottish history at Edinburgh University who taught Salmond medieval history at St Andrews, added: “When Edward came to Scotland in 1296 his conquest of the country was so sudden that people were suffering from shock. I don’t think anyone would have thought up the idea of hiding the stone.”

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