Is this Leonardo’s prequel to his famous portrait?

Art experts will this week claim that Leonardo da Vinci completed a version of the Mona Lisa some ten years before the famous painting which now hangs in the Louvre in Paris.

Known as the Isleworth Mona Lisa, the painting is a slightly larger size than the famous portrait and has long been the subject of debate over its authenticity.

However, the not-for-profit Mona Lisa Foundation, which was set up to conduct research into the work, is planning to put forward 'historical, comparative and scientific evidence' that will prove once and for all that the painting is by the Italian renaissance artist....