Cracking the missing Da Vinci code

Seracini thinks he knows, and he was recently given permission to re-start his search, which involves using the most modern detecting equipment to peer through a 500-year-old wall in the Palazzo Vecchio here. On that wall, in 2002, he found a tantalising crevice behind a Vasari fresco where the Leonardo may be.

If he succeeds, he could bring to light what one Leonardo scholar calls potentially 8220;one of the great art finds of all time.8221; Or he could find nothing. Or he could find the painting wrecked by time and its own defects. In any case, after three obsessive decades Seracini is very much on the hook.

One of the few certainties is that the painting, or at least a part of it depicting a fight for a standard, did exist on the wall of the Palazzo Vecchio, the old home of the Medicis.

8220;Friday the 6th of June, 1505, at the stroke of the 13th hour,8221; Leonardo wrote in one of his notebooks, 8220;I started to paint in the palace.8221;

His younger rival, Michelangelo, had also been commissioned to paint his own battle scene on the opposing wall. Michelangelo left for Rome and never began painting it.

But both men produced preparatory cartoons considered not only among the finest ever created but exemplary of the two strains of Renaissance the men embodied. Only a small portion was completed, though it was Leonardo8217;s largest painting, perhaps 15 feet by 20 feet, and as extraordinary as the cartoon.

Beginning in the 1560s, Vasari, who also built what is now the Uffizi museum, began to restructure the room. He enlarged it and covered both walls with his own grand battle fresco. Leonardo8217;s painting disappeared.

In 1970s, Seracini took an art course at UCLA from one of the leading Leonardo experts, an Italian professor, Carlo Pedretti. In 1975, Seracini returned to Florence and by chance linked up anew with Pedretti, who had begun a search for the lost painting, theorising that it lay behind Vasari8217;s fresco.

It was then, Seracini8217;s assistant, found on a flag in Vasari8217;s painting what he considered a sign from Vasari of what lay behind it: the words Cerca, trova, or 8220;Seek and ye shall find.8221;

The challenge before Seracini is that cannot touch the Vasari, a treasure on its own, and instead must find a way to peer behind it with machines that do not yet exist. He has several theoretical methods, including a machine that would detect the pigment Leonardo used.