Silvano Vinceti, the president of the national committee for the valorisation of historic heritage, said a dog with a lead, symbolising faith in Jesus' original message, had been detected behind the master's famed Virgin of the Rocks in the Louvre.
"That dog is an act of indictment by Leonardo da Vinci against the corruption of the papacy of the age," Mr Vinceti said.
The art expert, who was at the centre of the finding of Caravaggio's bones at Porto Ercole and the remains of the model for Mona Lisa in Florence in recent years, added that the discovery was made by Roberto Biggi, a researcher for the committee.
The dog was detected behind vegetation in the backdrop of the masterpiece.
"We achieved this result with a new work [method], via the use of a mix of the most advanced technologies and simple instruments," Mr Vinceti explained.
"A special magnifying glass enabled us to carefully examine every feature of the painting and then advanced Photoshop software enabled us to overlay, decompose and recompose it."
Mr Vinceti explained that the dog peeping out from the vegetation enables experts to give an entirely different reading of the Virgin of the Rocks.
“For Leonardo the dog has a precise meaning, 'no to disobey', as he himself writes in one of his folios. The leash, then, is an addition because it represented in medieval and Renaissance hunts the tool that enabled the feudal lord to stop dogs eating the prey,” he said.
"For Leonardo, therefore, the dog on a leash is the symbol of man who must obey God, the divine Commandments, Jesus, the life that Jesus perfectly embodied to express Christian love."
The discovery, therefore, consolidates an interpretation of da Vinci as the depository of a rigorous religious belief.
"Up until today his paintings have been addressed from the standpoint of technique and painting style," Mr Vinceti said.
"But we have lost sight of the fact that Leonardo, through the composition of his paintings, achieved a narration, expressed a thought that becomes image; when he writes 'painting is the beauty that clothes the truth' he clearly indicates his intentions."
With ANSA
