Sotheby’s trial provides a peek behind the curtain of private art sales

Testimony in a legal battle between a Russian billionaire and Sotheby’s, one of the world’s most prestigious auction houses, has pulled back the curtain on the opaque world of how the world’s most expensive art is sold to its most discreet buyers.

The case — in which oligarch Dmitry Rybolovlev has accused Sotheby’s of helping Swiss art dealer Yves Bouvier overcharge him by approximately $1bn on numerous purchases over a decade — has captivated the art world, giving a behind-the-scenes glimpse of private deals totalling tens or hundreds of millions of dollars. (Sotheby’s has denied any wrongdoing. Bouvier has not been named as a defendant in the lawsuit, and various other cases against him over his work for Rybolovlev have either been dismissed or settled.)

Lawyers for Rybolovlev argued that “transparency and accountability” are at the heart of the case. But Sotheby’s maintains that confidentiality and discretion are crucial to the world of high-end art sales to protect clients’ identities, prevent theft and stop any potential poaching by other auction houses.

While Sotheby’s is known for its prestigious public art auctions, a significant part of its business is brokering private deals directly between buyers and sellers. Those private sales are a particularly shrouded corner of the art market, where work changes hands through dealers such as Sotheby’s and identities are concealed on both sides of the purchase.

Often an owner will have no idea to whom they are selling, and the buyer little clue from where the art is coming. Sometimes works are never even displayed — instead living in storage, passing from hand to hand.

Over multiple days of testimony, Samuel Valette — the global head of private sales at Sotheby’s who sold many of the works to Bouvier, the Swiss dealer who worked for years with Rybolovlev — detailed the process by which works, including Leonardo da Vinci’s “Salvator Mundi”, were procured for Bouvier, his top…