Da Vinci code found painted in the eyes of Mona Lisa

Her enigmatic smile has teased art historians out of thought for centuries. But the eyes of the Mona Lisa also hold a secret.

After unveiling a mystery that could have come straight from the pages of The Da Vinci Code, experts are trying to decipher tiny numbers and letters painted into the eyes of the portrait.

Art historians found that by magnifying high-resolution images of Leonardo da Vinci’s masterpiece symbols can be seen. "To the naked eye the symbols are not visible but with a magnifying glass they can clearly be seen," said Silvano Vinceti, president of Italy’s National Committee for Cultural Heritage.

In the right eye appear to be the letters LV which could stand for the artist’s name, while there are also symbols in the left eye but they are not as defined.

Mr Vinceti said: "It is very difficult to make them out clearly but they appear to be the letters CE or it could be the letter B. You have to remember the picture is almost 500 years old so it is not as sharp and clear as when first painted."

He added: "While in the arch of the bridge in the background the number 72 can be seen, or it could be an L and the number two."

The painting, which has long been steeped in mystery with the true identity of the sitter remaining far from certain, featured in the Dan Brown novel The Da Vinci Code, which was turned into a film starring Tom Hanks.

The lead character interprets secret messages hidden in the Mona Lisa and da Vinci’s other works including The Last Supper.

Mr Vinceti, who has gone to Paris to examine the painting in the Louvre gallery, said he was put on to the mystery after his fellow committee member, Luigi Borgia, found a musty book in an antique shop.

The 50 year-old volume describes how the Mona Lisa’s eyes are full of signs and symbols. Mr Vinceti said: "We are only at the start of this investigation and we hope to be able to dig deeper into this mystery and reveal further details as soon as possible. It’s remarkable that no one has noticed these symbols before."

Mr Vinceti’s committee is asking for permission to exhume da Vinci’s remains from his tomb at Amboise Castle in the Loire Valley. They want to see if the artist’s skull is there so they can try to recreate his face and establish if the Mona Lisa is a self-portrait as many people believe.

Some historians believe that da Vinci was homosexual and his love of riddles led him to paint himself as a woman. Other theories state that the sitter is Lisa Gheradini, the wife of a Florence merchant, or the artist’s mother.