Sometime toward the end of 1939, Frida Kahlo completed “La Mesa Herida,” an oil painting that represents the grief she felt after separating from her husband, the artist Diego Rivera.

The piece, one of Kahlo’s few large works, shows blood dripping from a table, where she sits surrounded by a Pre-Columbian Nayarit figurine, a skeleton, two children and a deer. The painting was first exhibited in the International Surrealism Exhibit at Inés Amor’s Gallery of Mexican Art in Mexico City, and then in Warsaw in 1955, where it vanished.

The painting’s whereabouts have remained a mystery for decades but now, one Spanish art dealer thinks he may have found it. According to Dazed, Cristian López has claimed the original is in a warehouse in London. He told the Associated Press that it’ll be sold to “whoever proves genuine interest and the ability to pay the figure of 40 million euros.” Said person “can spend as much time as wanted with their experts analyzing the work,” he says.

That last part is tricky: Already, experts doubt it’s the real painting, noting obvious differences in photos and information López has provided. For starters, they note that the work Lopez is promoting seems to be on canvas, whereas Kahlo’s original was painted on wood, according to the Observer. Hans-Jérgen Gehrke, an art collector who runs a museum dedicated to Kahlo in Germany, spoke to the AP and reiterated how “implausible, if not directly ridiculous” it would be if it were the real painting.

“There are thousands of Frida Kahlo fakes,” Gehrke said. “She is possibly the artist who has painted more dead than in life.”