New York, June 10 (TIWN / IANS) Researchers have found that the famed smile of Mona Lisa painted by Leonardo da Vinci may not be genuine because of its asymmetry.

A team of British researchers believe they have finally discovered the secret behind da Vinci's Renaissance composition of the woman believed to be Lisa Gherardini, the wife of wealthy Florentine silk merchant Francesco del Giacondo and a member of Florence and Tuscany's Gherardini family.

Next to the thousand-mile gaze, the question that has persistently stumped scholars and admirers of the painting is whether Mona Lisa is slightly smiling or slightly grimacing. Determined to find a method behind da Vinci's technique, experts from two universities in the United Kingdom examined how a viewer's perspective of the painting impacts their perception of it, ArtNet News reports.

To help analyze 'Mona Lisa,' the researchers compared the painting to an earlier work of da Vinci's, 'La Bella Principessa' (c. 1496), a portrait of a Milanese Duke's young illegitimate daughter, which creates a very similar effect.