SAN FRANCISCO, California (CNN) -- The "Mona Lisa" has long been shrouded in mystery, including one long-standing question about the famous lady: What happened to her eyebrows and eyelashes?

A French engineer and inventor examined the famous painting with a camera of his own design.

Now, a French engineer and inventor says he's uncovered part of the enigma.

Pascal Cotte announced at a press conference Wednesday that he has found definitive proof that when Leonardo da Vinci painted the original portrait he included "Mona Lisa's" lashes and brows.

Cotte examined the world's most famous painting using a high-definition camera of his own design.

The device scanned a 240-million pixel image using 13 light spectrums, including ultra-violet and infrared.

The resulting ultra-high resolution photograph of 150,000 dots per inch yielded a reproduction of the "Mona Lisa's" face magnified 24 times. And there Cotte found the evidence he sought -- a single brushstroke of a single hair above the left brow. Watch as expert announces findings on "Mona Lisa" »

"One day I say, if I can find only one hair, only one hair of the eyebrow, I will have definitively the proof that originally Leonardo da Vinci had painted eyelash and eyebrow," said Cotte.

So, if she once had lashes, where did they go? Possibly faded pigment, Cotte suggested, or possibly a poor attempt to clean the painting.

"And if you look closely at the eye of 'Mona Lisa' you can clearly see that the cracks around the eye have slightly disappeared, and that may be explained that one day a curator or restorer cleaned the eye, and cleaning the eye, removed, probably removed the eyelashes and eyebrow," he said.

Cotte's high resolution camera led him to numerous additional discoveries about the enigmatic artwork.

The infrared layer of the image shows that the fingers of the "Mona Lisa's" left hand were originally painted in a slightly different position than in the final portrait.

Cotte said the change in position was the result of a lap blanket held by Leonardo's model. In today's faded image the blanket is all but obscured, but the highly detailed camera detected the faded pigment.

"It was really the first time that we have this kind of position of the arm," Cotte said, "and after Leonardo da Vinci, thousands of painters have made a copy of this position but without understanding why we have this position. The real justification of the position of the wrist is to hold the blanket on her stomach. It's really a great, for me, it's really a great discovery."

One of the results of Cotte's work is a "virtual" restoration of the painting, an exact replica showing the original colors as they would have looked when the painting was new.

The skin tones of Leonardo's model appear as a warm pink and the sky behind her is a glowing blue, far different from the gray-green tint that covers the artwork today. That dark patina is the result of 500 years of aging, according to Cotte.

Cotte presented numerous other findings within the infrared layer he photographed.

The researcher said the "Mona Lisa's" smile was originally slightly wider than it appears today, and, in fact, so was her entire face.

Leonardo kept this painting with him for more than a decade, and is said to have worked on it up until his death. The Renaissance artist once said, "Art is never finished, only abandoned."

The results of Cotte's study are on display at the Metreon in San Francisco, as part of the exhibit "Da Vinci: An Exhibition of Genius." E-mail to a friend

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