Archaeologists have unearthed a skeleton in a rare state of preservation in Florence.

They believe it may be the body of Lisa Gherardini, the Florentine noblewoman widely believed to have served as the muse for Leonardo da Vinci's Mona Lisa.

It could be a crucial step towards unravelling the mystery of the woman with the world's most enigmatic smile.

Art historian Silvano Vinceti told the BBC: "We are entering the heart of this search, which is the most important moment."

Alan Johnston reports.