Veil suggests Mona Lisa model was pregnant

As if her enigmatic smile had not inspired enough debate over the centuries, the mysterious Mona Lisa was the subject of renewed controversy yesterday. Scientists now claim the young woman depicted in Leonardo da Vinci's 16th century masterpiece was either pregnant or had recently given birth.

"Thanks to laser scanning, we were able to uncover the very fine gauze veil Mona Lisa was wearing on her dress. This was something typical for either soon-to-be or new mothers at the time," explained Michel Menu, of the French Museums' Centre for Research and Restoration.

The Mona Lisa, or La Gioconda, was in fact Lisa Gherardini, the wife of the wealthy Florentine silk merchant Francesco del Giocondo. Aged 24, when Da Vinci began painting her in 1503, she outlived her husband and had five children. Some experts believe the portrait may have been commissioned to commemorate the birth of her second son. Da Vinci was still working on the piece when he emigrated to France in 1516 and is believed to have finished it just before his death three years later.

The new findings emerged after the most extensive three-dimensional scan ever undertaken on the painting. Scientists from the National Research Council of Canada (NRC) used laser and infrared scans, 10 times finer than a human hair, to reveal details previously hidden by darkened paint and varnish.

These include a slightly different posture, the fact her hair was originally in a bun and the gauze dress, which they say was worn by Italians in the early 16th century when they were pregnant or had just given birth.

Yesterday, however, Mr Menu explained that all the secrets behind the painting have yet to be revealed. Da Vinci's smoky technique continues to elude experts. "Our laboratory is trying to uncover Da Vinci's techniques. We particularly want to understand how he painted shadows, the famous sfumato effect," he said.

The French artist and art historian Jacques Franck ­ a controversial figure but an acknowledged authority on Da Vinci ­ claimed this year to have cracked the conundrum which has defeated art experts for almost 500 years. He insisted that he could approximate it with an ultra-fine hatching or criss-crossing of brush strokes.

Other scholars remain sceptical and continue to examine the technique.

This is not the first time that the "Mona Lisa was pregnant" theory has surfaced. In 1959 a British doctor, Kenneth D Keele, published a paper in the Journal of the History of Medicine and Allied Sciences insisting that the woman in the world's most famous painting had a " puffy neck" caused by an enlarged thyroid gland, a sure sign she is pregnant.