Eleven days later, the owner texted images of the artwork to Mr. Schorer, who said he drove straight to the man’s house, where, he said, the man and his wife lived simply. Mr. Schorer sat down at the kitchen table to look at the piece.
“It was an either a masterpiece or the finest counterfeit I had ever seen,” he claimed.
Mr. Schorer, who specializes in recovering missing art, paid the individual a $100,000 advance to sell the drawing, he said. (The particular conditions are confidential, but both will get money when it sells, he said.) Mr. Schorer would forfeit his advance if the piece turned out to be a counterfeit.
Mr. Phillipson said his friend, the owner of the drawing, declined to speak.
Three days later, Mr. Schorer took a flight to England to rush the drawing into the hands of Jane McAusland, a paper conservator who advises museums, dealers and auction houses. She did not respond to emails this week from The Times.
Three weeks after his visit, Ms. McAusland told him that the drawing had been ruined with tea or coffee to make it look like an antique, Mr. Schorer said. But he requested her to look again, and she answered by email the next day with an image. He clicked on it, and the photo showed a translucent light shining through the paper.
“It had the trident watermark, which is only in Albrecht Dürer’s drawings,” he remarked. “My mind was blown.”
Dürer’s chosen medium was a special paper created by his sponsor, Jacob Fugger, one of the richest men who ever lived. Only Dürer’s workshop had access to the paper, which had Fugger’s signature watermark, according to Christof Metzger, a Dürer expert and the chief curator of the Albertina Museum in Vienna.