Actor and comedian Steve Martin is an avid art collector. In 2004, he bought a 1915 painting by Dutch artist Heinrich Campendonk called "Landscape with Horses." Its authenticity had been confirmed by "a Campendonk expert," according to Der Spiegel, and Martin paid over $900,000 for it.
When he resold the work at Christie's in 2006 it fetched only $655,000. It was revealed to be a forgery by German painter Wolfgang Beltracchi, who admitted to forging the works of more than 50 artists. He was sentenced to a six-year prison term in 2011.