Researchers into the provenance of a painting dubbed the "Early Mona Lisa" reported on Monday they had identified an English noble who probably bought it in Italy in the late 18th century and a country house where it was found in 1911.

The revelations came as the work went on show for the first time in Singapore in a display about the portrait and Leonardo da Vinci, who a Swiss foundation holding it argue painted it before the version in the Paris Louvre.

"We feel these latest discoveries and new scientific analysis just carried out leave little doubt that it is Leonardo's work," said David Feldman, a Geneva-based auctioneer and vice president of the Zurich Mona Lisa Foundation.