This photo shows an endoscope being thread into the Vasari wall to find signs of the lost Leonardo painting "The Battle of Anghiari" in Florence's Palazzo Vecchio. (DAVE YODER/National Geographic - AFP/GETTY IMAGES) 
 
 Historian Maurizio Seracini of the University of California San Diego suspected that the work was hidden behind the Vasari wall because of a clue that the artist left: A soldier in Vasari’s work holding a small flag that said: “He who seeks, finds.” 
 
 A research team has drilled small holes in the Vasari work and encountered an air cavity. A sample of the paint that came back on the probe was “was similar to black pigment found in brown glazes on Leonardo’s Mona Lisa and St. John the Baptist, identified in a recently published scientific paper by the Louvre, which analysed all the Da Vinci paintings in its collection,” the team said in the Guardian. But Seracini, when surveying the hall using laser and radar methods, discovered air gaps behind the fresco and suspected that Vasari built a wall in front of Da Vinci's unfinished masterpiece and painted it over with a fresco in order to preserve it.
– Indefatigable art experts believed they've discovered the location of a long-sought Leonardo Da Vinci masterpiece hidden behind another painting in Florence. A California team searching for the masterpiece Battle of Anghiari are convinced it's painted on a wall of the Palazzo Vecchio—behind another painting by Giorgio Vasari. They sampled the chemical content of the red, black and beige paint beneath Vasari's fresco, and discovered it matched the paint used on the Mona Lisa and Da Vinci's St. John the Baptist, reports ABC News. An unusual red lacquer typically used for oil painting is also consistent with Da Vinci's plan to do his battle painting in oil, notes researcher Maurizio Seracini, a professor at UC-San Diego. Though much work remains to be done, "the evidence suggests we are searching in the right place," he said. Other experts are not so convinced, reports the Washington Post, and call Seracini's claims "propaganda," though the mayor of Florence is certain the painting is hidden behind Vasari's. Da Vinci began painting Battle on Anghiari in 1505, but stopped a year later when he left Florence. Vasari's Battle Marciano in Val di Chiana was painted in 1563 in the Palazzo Vecchio when the Hall of the 1500s was being remodeled. Da Vinci's painting was thought to be destroyed then. But Seracini discovered spaces behind Vasari's painting, and began to suspect that the Da Vinci was still on the real wall underneath a kind of false front made for the newer fresco. Vasari himself may have left a tantalizing clue. One of his painted soldiers holds a flag reading: "He who seeks, finds."