Updated

Her enigmatic smile holds a secret -- one scientists hope to finally crack.

The identity of the raven-haired beauty painted by Leonardo da Vinci in 1504 has long been suspected to be Lisa Gheradini Del Giocondo, the wife of a rich silk merchant. But proving that suspicion has been an archaeological investigation worthy of a Dan Brown novel.

The latest quest began last year, when Silvano Vinceti -- who is charge of the National Committee for the valuation of historic, cultural and environmental assets -- uncovered several skeletons in the basement of a Florence convent, one of which they believe to be the model’s.

[pullquote]

But which?

More On This...

To pinpoint the exact remains of Mona Lisa, Vincenti told the ANSA news service he plans to open the tomb of Del Gioncondo’s relatives, stone coffins sealed for the past 300 years, to see if DNA from those skeletons match any of the ones found last year.

"Right now we are carrying out Carbon-14 tests on three of the eight skeletons found in St. Ursula, which could be the age Lisa Gherardini was when she died," Vinceti said. "The Carbon-14 test will tell us which of the three dates back to the 1500s. Only then will we know which skeleton to do the final DNA test on."

The family tomb of Del Giocondo lies in the Martyr’s Crypt behind the main altar of Santissima Annunziata church in Florence, ANSA said. It holds Gherardini’s husband and their two sons.

The hunt for Mona Lisa’s remains has gone on since a 2007 book pegged her identity to the Del Giocondo clan, something most modern art historians now agree with, and last resting place to former convent.

"After 1500, only two women were buried here: Mona Lisa Gherardini, in 1542, and another noblewoman, Maria del Riccio," said a statement from researchers.