In 2006 The Cardsharps was sold to the late collector and scholar Sir Denis Mahon for just over $65,000 at an auction at Sotheby’s in London. At the time of the sale, Sotheby’s identified the work as being by a “follower” of the Italian master, Caravaggio (1571-1610). However, after his purchase, Mahon identified the work as a Caravaggio original and obtained an export license for the work that put its value at $15.5 million according to a claim filed at London’s High Court of Justice.

Due to their failure to identify The Cardsharps as an authentic Caravaggio painting, Sotheby’s is being sued by Lancelot William Thwaytes, who consigned the work to the 2006 auction. Thwaytes is now seeking unspecified damages, interest, and costs relating to the price difference between the painting’s 2006 selling price and what he believes it was actually worth on the open market that year had it been properly attributed to Caravaggio. Thwaytes claims that Sotheby’s was negligent in its research prior to the work’s sale, leading to its extraordinarily low selling price.

However, Sotheby’s stands behind its belief that the painting is a copy and not a work by Caravaggio’s hand, citing Caravaggio expert Professor Richard Spear and several other leading scholars. Sotheby’s added that their view was supported by the market’s reception to the painting when it was put up for auction.

Mahon, who passed away in 2011, donated 58 works from his collection worth around $155 million to various U.K. galleries.