Scientists in the Italian city of Florence have opened a tomb to extract DNA they hope will identify the model for Leonardo da Vinci's Mona Lisa.
The tomb contains the family of Lisa Gherardini, a silk merchant's wife who is believed to have sat for the artist.
Writer and researcher Silvano Vinceti plans to compare DNA from the bones with that of three women buried at the nearby convent of Saint Ursula.
Lisa Gherardini died there as a nun in 1542.
It is hoped that some of the bones will belong to at least one of her blood relation, probably her son, Piero.
"When we find a match between mother and child - then we will have found the Mona Lisa," said Mr Vinceti.
He added that once a DNA match is made, an image of Gherardini's face can be generated from the skull and compared with the painting.
Leonardo da Vinci took about 15 years to complete what has become one of the most famous paintings of all time.
One of the artist's favourite paintings, he carried it with him until he died in 1519.
It was acquired by King Francis I, who ruled France from 1515 to 1547. The painting was put on permanent display in the Louvre in Paris at the end of the 18th century.