Art historians at the Louvre have been accused of "overcleaning" a masterpiece by Leonardo da Vinci, leaving the painting with a brightness that was never intended.

Two of France's top art experts have registered their displeasure at the cleaning of The Virgin and Child with Saint Anne by stepping down from their posts at the Paris museum's advisory committee responsible for its restoration, according to reports.

Influence: It is said that the British influence on restoration has helped
to sway the Louvre

The resignations of S �gol ne Bergeon Langle and Jean-Pierre Cuzin -- former specialists in conservation and painting respectively -- will be seen as a major embarrassment for the Louvre.

Bergeon Langle is regarded as France's national authority on the art and the science of restoring paintings. She was director of conservation for all of France's national museums.

She said, "I can confirm that I have resigned from the international consultative committee, but my reasons I am reserving for a meeting with the president-director of the Louvre, Henri Loyrette."

The restoration has divided the committee between those who believe the painting is now too bright and those who regard the cleaning as moderate. Seventeen years ago, the Louvre abandoned an earlier attempt to clean the painting amid fears about how the solvents were affecting the sfumato, the Renaissance master's trademark effect for blurring contours. Since then, it appears that the British influence on restoration has helped to sway the Louvre.

Meanwhile, Vincent Pomar de, the Louvre's head of paintings, defended its cleaning process saying, "Rarely has a restoration been as well prepared, discussed and effected, and never will it have benefited from such effective techniques."