Las Vegas billionaire Frank Fertitta III is suing a respected Swiss curator accused of standing behind the authenticity of a Mark Rothko painting that turned out to be a fake. Feritta acquired “Untitled (Orange, Red and Blue)” from New York’s disgraced Knoedler gallery in 2008. He paid $7.2 million for the canvas.

Oliver Wick, a Swiss Rotko expert and specialist in American paintings, received $300,000 for the sale. According to court documents, Wick “was aware of substantial evidence that the painting was a forgery” and “conducted no independent research into the authenticity of this fake Rotko.” The painting had been exhibited at the Fondation Beyeler museum in Basel, Switzerland, where Wick was a curator.

Knoedler, which closed in 2011, has been accused by multiple clients of selling forged paintings. The forgeries, which were presented as authentic works by Rothko, Jackson Pollock, Robert Motherwell, Franz Kline, and Willem de Kooning, had been painted by a Queens-based Chinese artist and sold to Knoedler by Glafira Rosales, a Long Island art dealer. Rosales pleaded guilty to nine charges, including wire fraud, tax fraud, and money laundering, last September. During her 15-year scheme, Rosales swindled unsuspecting customers out of over $80 million.