A bloody skirmish between knights, a clutch of figures rebuilding a ruined temple and even an elephant were carefully laid out by Leonardo in the preparatory “under-drawing” for his Adoration of the Magi.

In the version of the painting known to the world, in which much of the underdrawing is reproduced, these elements have been hidden.

Parts of the original design were deliberately obscured — sometimes with swipes of charcoal — because in 15th century Florence they were deemed unsuitable for a picture of the infant Jesus and the wise men.

Maurizio Seracini, an engineer who makes scientific investigations of artworks, discovered the discrepancies in 2002 using multispectrum imaging. His work helped to establish that the Adoration was only partly the work of the Renaissance genius.

Signor Seracini demonstrated that the brown monochrome painting on top of the drawing was carried out by an anonymous, minor artist about 20 years after Leonardo had finished and abandoned the preparatory work.

Chiara Pagnini, an art historian based in Rome, agrees. “Someone like Leonardo would never do his preparatory drawing and then paint something different on top.The most plausible explanation is that the people who commissioned the work didn’t like it.”

The infrared images showing the concealed elements had been seen only by a few art specialists until Signor Seracini unveiled them publicly for the first time in Florence this week. A video illustrating his findings is at www.florence.tv.

Signor Seracini’s ability to penetrate the mysteries of The Adoration of the Magi attracted the attention of the novelist Dan Brown when he was writing The Da Vinci Code. Brown devoted half a page to the work in his novel, making the scientist the only living person to feature in the book.

The Adoration of the Magi was a common theme in Renaissance art. Leonardo was commissioned to do a version by a community of monks in Scopeto, near Florence, in 1481. They were probably aghast when they saw the work being developed by the 29-year-old artist. “They almost certainly didn’t want a bloody battle going on a few inches from the Madonna’s head,” Signor Seracini said.

In the brown painting that now hangs in the Uffizi gallery in Florence, the fighting knights on horseback have gone, as have the prone figures — presumably corpses — on the ground. All that can be seen is a pair of prancing horses.

The anonymous painter also covered up several figures who were rebuilding the ruins in the background. Signor Seracini suggests that the monks may have wanted the past to appear abandoned with the coming of Christ. “The main difference in the under-drawing is that it is much busier, there’s lots of movement. About half the human figures disappear in the painting phase,” he said.

Signor Seracini and the art historian Antonio Natali believe that Leonardo planned a battle scene and temple being rebuilt in the background to symbolise war and peace, drawing on the visions of the Old Testament prophet Isaiah. The tiny elephant that Signor Seracini spotted might have been a symbol of exotic transport used by the Magi.

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