An ultra-rare Ferrari 250 GT SWB California Spyder from 1961, one of only a few dozen ever made, hammered for a record-breaking $18.5 million at an auction at Artcurial in Paris on Friday, according to a press release. In addition to scarcity of the model, what makes the car remarkable is its unusual provenance.

Having once belonged to actor Alain Delon, it is part of a trove of 60 rare classic cars discovered on a farm in western France. The collection, which includes brand names like Bugatti and Maserati, is believed to have been forgotten for half a century.

Artcurial managing director Matthieu Lamoure likened the find to stumbling upon the car world’s equivalent of the tomb of Egyptian pharaoh Tutankhamun.

Lamoure and specialist Pierre Novikoff received a tip about the farm and upon visiting found several large makeshift structures containing the cars, many of them rotting and barely protected from the elements. “This was somewhere between a metallic graveyard and a museum,” described Novikoff.

The trove belonged to automobile enthusiast Roger Baillon, who purchased the farm in the 1950s with the intention of creating a museum. Unfortunately, as his business declined in the 1970s, he had to sell off parts of the collection, and the museum was never established.

Delon, who owned the car for two years, was photographed in it with Jane Fonda and Shirley MacLaine. Historians had assumed it was lost forever.

According to ArtDaily, Delon has criticized the auction house for using his name to push up the price of the car, stating: “Everything that has been indicated, mentioned, written about the sale of this car has been done without my consent.”

Read more about vintage car sales in Vintage Cars Overtake Art on Luxury Asset Racetrack and Records Fall at Bonhams Classic Auto Auction.