Scotland's iconic painting attributed to French artist

It's enough to send a cold shiver down the spine of the most patriotic art lover.

One of Scotland's most famous paintings, which has been credited with presenting a portrayal of the country and its people in a single iconic image, may actually have been created by a Frenchman. The Reverend Robert Walker Skating on Duddingston Loch is one of the country's most revered paintings and has always been credited to the Edinburgh artist Sir Henry Raeburn.

New evidence is about to emerge that will suggest the image, which hangs in the National Gallery of Scotland and has been immortalised by Enric Miralles in the design of the new Holyrood building and adorns the cartoons and Christmas cards of popular culture, was actually created by Henri-Pierre Danloux, a little-known French painter.

Stephen Lloyd, a senior curator at the Scottish National Portrait Gallery, has thrust the painting into "attributional limbo" by claiming the Frenchman painted it. Dr Lloyd, an expert on 18th and 19th century British portrait painters, is keeping many details about his eight-year research secret until he formally presents his findings at a lecture later this month, but he is convinced that Danloux, a refugee painter from the French court during the revolution, was the true artist.

Dr Lloyd claims one of the signs is the type of canvas used. About 98 per cent of the time Raeburn used a broadly woven herring-bone canvas, which was ideally suited for his style of brushes loaded with paint. "In a few cases he uses a vertical, closely woven canvas but Danloux always used that very closely vertical woven canvas, which was typical of French artists," said Dr Lloyd.

Although unsigned, the figure of the skating minister is painted on a closely vertical woven canvas. The smaller size of the painting, its unusual composition and the brush work also serve to make it very different from any other Raeburn.

"Raeburn did more than 1,000 paintings and never signed one of them so it's not unusual that this work is unsigned," said Dr Lloyd. "Much of Danloux's work is also unsigned. A lot of artists of that period did not sign their work. But you don't need a signature to realise this is not a Raeburn. It is so different from his other paintings."

Dr Lloyd's ideas have found favour with Michael Clarke, the National Gallery of Scotland's director, who says he can be persuaded either way, and Sir Timothy Clifford, director general of the National Galleries of Scotland. But others, such as Jamie Stone, a Liberal Democrat MSP and Raeburn enthusiast, refuse to accept the painting could have been created by anyone else. "I think the portrait of Reverend Walker is definitely the work of Raeburn who was a friend of Walker," said Mr Stone who claims the wintry light and soft colours on the scarf around the skating minister's neck are typical of Raeburn's style.

Hardly anyone knew of the artwork, which is not mentioned in any of the early books on Raeburn, until it was bought for the nation in 1949, when Ellis Waterhouse, then the NGS director, bought it at Christie's in London for £525.

Dr Lloyd said: "It doesn't matter who it is painted by, it is a beautiful image and it is still distinctly Scottish."