Sabrina Sforza Galitzia said the clues were to be found in da Vinci’s Last Supper mural. The central half-moon window, or lunette, above his painting of Christ with his disciples before the Crucifixion contains a “mathematical and astrological” puzzle which she has deciphered, she said.

She claimed to have worked out that da Vinci foresaw the end of the world in a “universal flood” which would begin on March 21, 4006 and end on November 1 the same year. Documents showed that he believed that this would mark “a new start for humanity”, Ms Sforza Galitzia said.

“There is a da Vinci code — it is just not the one made popular by Dan Brown,” she said.