Pascal Cotte said he has spent more than 10 years using the technology to analyse the painting.

He claims the earlier portrait lies hidden underneath the surface of Leonardo's most celebrated artwork.

A reconstruction shows another image of a sitter looking off to the side.

Instead of the famous, direct gaze of the painting which hangs in the Louvre Museum in Paris, the image of the sitter also shows no trace of her enigmatic smile, which has intrigued art lovers for more than 500 years.

The Louvre Museum has declined to comment on his claims.

(BBC News)