The Mona Lisa's enigmatic smile is beginning to fade.
Curators at the Louvre, the Paris museum where the 500-year-old painting is housed, have warned that Leonardo da Vinci's masterpiece was showing signs of rapid deterioration, report agencies.
"The thin panel of poplar wood, on which this mythical image is painted, is more warped than it was previously," and the damage is causing "some worry," museum curators declared on Tuesday.
They said da Vinci had used several layers of coating on the wood before painting in oil to give Mona Lisa her luminous sheen. He also used a weak layer of turpentine to allow him to apply glaze. But five centuries of accumulated dust as well as chemical changes in the varnish are starting to take their toll.
The curators said a special investigative team will now look at ways to restore the painting, but that it will be a tough task. Experts will have to precisely determine not just the materials used in the painting, but also how they change with age.
The painting is said to attract over six million visitors a year to the Louvre, and the curators said that the 'lady with mysterious smile' would continue to be exhibited during the investigation by the expert team.
La Giaconda was painted by Leonardo da Vinci in 1503. After his death, the painting was acquired by a French king and became a part of France's national collection. It was stolen in 1911 from the Louvre by an Italian, but recovered and restored two years later.