The Smiling Girl, thought to be by Johannes Vermeer, was donated by collector Andrew W. Mellon in 1937 to the National Gallery of Art in Washington, D.C. Now widely considered to be a fake, the painting was claimed by Vermeer expert Arthur K. Wheelock Jr. in a 1995 study to be by 20th-century artist and forger Theo van Wijngaarden, a friend of Han van Meegeren. Wikipedia