Italian renaissance artist Leonardo da Vinci may have painted a prequel to his master piece Mona Lisa, ten years earlier to the famous work which now hangs in the Louvre in Paris, experts claim.
Known as 'Isleworth Mona Lisa', the earlier version is slightly larger in size than Mona Lisa and has been a subject of debate over its authenticity for long, according to reports.
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 renaissance artist.
The claims of the Swiss-based consortium which owns the painting are supported by Professor Alessandro Vezzosi.
Mr Vezzosi will present evidence alongside Professor Carlo Pedretti of the Armand Hammer Center for Leonardo Studies at the University of California.
The 'Isleworth Mona Lisa' was discovered shortly before the World War I by Hugh Blaker, an English art collector, while looking through the home of a Somerset nobleman.
He bought the painting and took it to his studio in Isleworth, London, from which it takes its name.
Art critics conjectured that Leonardo had in fact painted two portraits of Lisa del Giocondo, with one hanging in the Louvre and the other which Mr Blaker bought.
Mr Blaker sold the portrait to an American collector, Henry F Pulitzer, who in turn left it to his girlfriend.
On her death, it was bought by a consortium of unnamed individuals who have kept it in a Swiss bank vault for 40 years.
However, Martin Kemp, emeritus professor of the history of art at Oxford disputes the claims that 'Isleworth Mona Lisa' is indeed the work of da Vinci.
"So much is wrong," Kemp said. "The dress, the hair and background landscape. This one is also painted on canvas, which Leonardo rarely did," he said.
Like majority of da Vinci's works, Mona Lisa in the Louvre is in fact painted on wood.
While the lady in the Isleworth Mona Lisa does appear to be a younger version of the model in the more famous painting, but Kemp believes this did not prove it was produced by the master artist.