Leonardo da Vinci’s famous painting in the Louvre Museum in Paris has been subjected to 10 years of study using reflective light technology.
Pascal Cotte, co-founder of Lumiere Technology in Paris, has spent a decade analysing the Mona Lisa and claims an earlier portrait lies hidden underneath the one which attracts so many visitors to the Louvre.
In a reconstruction of his analysis, there is another image of a sitter looking off to the side, the BBC reported.
In this image, the sitter does not smile like in the famous painting.
The Louvre Museum has declined to comment on his claims.
Mr Cotte used a technique called Layer Amplification Method (LAM) to delve deeper into the Mona Lisa.
This projects a series of lights on the painting and the reflections are then measured by a camera. From those measurements, the hidden layers of the painting can be reconstructed.
Mr Cotte said: “We can now analyse exactly what is happening inside the layers of the paint and we can peel like an onion all the layers of the painting.
“We can reconstruct all the chronology of the creation of the painting.”
It has long been believed that the woman in the Mona Lisa, painted between 1503 and 1517, is Lisa Gherardini, the wife of a silk merchant in Florence, Italy.
But Mr Cotte claims the subject is another woman entirely.
“The results shatter many myths and alter our vision of Leonardo’s masterpiece forever,” he said in The Secrets of the Mona Lisa programme, which will be broadcast on BBC Two at 9pm tonight.
“When I finished the reconstruction of Lisa Gherardini, I was in front of the portrait and she is totally different to Mona Lisa today. This is not the same woman.”