AS Monaco owner Dmitry Rybolovlev has sued Sotheby’s in New York for $380m (€329m), accusing the auction house of assisting in a fraud.

The Russian billionaire says Sotheby’s helped a Swiss art dealer defraud him, according to a report by AFP.

Rybolovlev bought 38 art masterpieces over a decade, spending more than €1.82bn, later accusing seller Yves Bouvier of inflating prices. He says Sotheby’s assisted Bouvier by over-valuing paintings.

“Mr Rybolovlev’s latest desperate lawsuit is entirely without merit,” Sotheby’s said in a statement.

“We will be moving to dismiss the action in New York and at the same time we will continue to pursue our case through the Swiss courts. Sotheby’s had no insight into what Bouvier did with the pieces that he bought.”

The case continues.