A painting by Pablo Picasso stolen in a dramatic heist six years ago has been found buried in a Rotterdam forest. Or, at least, it seemed that way at first. But what appeared to be a cinematic recovery has now been revealed to be a hoax. Two Belgian film directors planted a forged version of the painting—recovered 10 days ago by an expert on the theft—as an elaborate prank.

The painting in question, Picasso’s Harlequin Head, is valued at €800,000 ($913,860) and was among seven paintings that were stolen from Rotterdam’s Kunsthal museum in a major heist in 2012. The thieves entered through an unlocked door and pilfered valuable works by Henri Matisse, Paul Gauguin, Claude Monet, and Lucian Freud. One year after the robbery, two Romanians operating as part of an organized crime ring, Radu Dogaru and Eugen Darie, pleaded guilty to the theft. The paintings have not yet been recovered.

The latest intrigue began just over a week ago, when Dutch writer Mira Feticu, who penned a novel based on the heist in 2015, received an anonymous tip with instructions on how to find the lost painting by Picasso. The note led her on an “X marks the spot” chase, which the author excitedly documented, all the way to a forest in Romania. There, she dug up what appeared to be the painting, wrapped in plastic and buried beside a tree.

Feticu returned the supposed Picasso to authorities on Saturday evening for further examination.

The find was surprising: At the time of the court case, Radu Dogaru’s mother claimed that she had burned the seven stolen artworks in an attempt to destroy any evidence that could be used against her son. Experts did find 19th-century nails in the woman’s stove, though her lawyer pointed out that none of the works used nails and the woman later recanted her statement.

On Sunday night, the author went to the press to explain what she now realized was the truth: She was the victim of a performance by two Belgian directors, which she told the AFP was a “publicity stunt.” Earlier that day, she  received an email from the Antwerp-based pranksters and directors, Yves Degryse and Bart Baele, who told Feticu that the anonymous letter was part of a upcoming project called True Copy. The two are artistic directors of the Belgian film production company, Berlin.

Their website states that the ongoing project is part of “a performance about Dutch master forger Geert Jan Jansen” that “revolves around the life of a forger and the inherent question of the value of truth.” The film True Copy premiered last Thursday in Antwerp. The production company says more information about their stunt will be revealed in the coming days, once Baele and Degryse have spoken with Feticu.