Skeleton found in Florence that of Mona Lisa's model?

Archaeologists believe they are about to unravel the enigmatic smile behind Leonardo da Vinci's masterpiece Mona Lisa after discovering what may be skeleton of the woman who posed for the world's most famous painting.

Lisa Gherardini, the second wife of wealthy Florentine silk merchant Francesco del Giocondo, is recorded as buried in Saint Ursula convent and the team of Italian art historians archaeologists believe they have her remains.

 The team led by Silvano Vinceti, a former TV producer, is attempting to exhume and identify Gherardini's remains by sending the bones to universities in Italy and abroad, where they will be checked against the DNA of two confirmed relatives of Gherardini,.

"Once we identify the remains we can reconstruct the face, with a margin of error of two to eight per cent. By doing this, we will finally be able to answer the question the art historians can't: Who was the model for Leonardo?" Vinceti was quoted by the paper as telling CNN.

It remains one of the great mysteries of the art world - what is the secret behind the mysterious smile boasted by the woman in the Mona Lisa, the world's most famous painting.

There has been centuries of debate over the 77 by 52 cm picture, also know as 'La Gioconda'.

Most modern historians agree that the lady depicted in the Mona Lisa was Lisa del Giocondo, who became a nun after her husband's death. She died in the convent on July 15, 1542, aged 63.

However, Vinceti is not certain whether the painting that now hangs in the Louvre in Paris is of her.

"When Leonardo began painting the model in front of him, he did not draw that metaphysical, ironic, poignant, elusive smile, but rather he painted a person who was dark and depressed," he said.

Vinceti believes the famous smile was added later and may belong to da Vinci's longtime assistant Gian Giacomo Caprotti, also rumoured to have been his lover.

Some art historians say the 'Mona Lisa' is actually a sneaky self-portrait. An archaeological team began digging at the abandoned Convent of Saint Ursula last year.

The team first had to dig through thick concrete, laid down ahead of plans to turn the convent into an army barracks.

They quickly struck gold, finding a crypt they believe to have been Lisa's final resting place and soon after they unearthed a female-sized human skull.