PARIS — A French couple who sold an “extremely rare” African mask for €150, only to find out it was worth millions, saw their motion to cancel the original sale rejected by a court in the south of France.

The couple, who are in their 80s and retired, argued there had been an “authentication error” and that the mask’s buyer, a small town second-hand dealer, knew how much the object was really worth when he bought it in 2021.

But the court rejected their claims, saying the couple hadn’t made any attempt to get the mask valued before selling it.

"Their negligence and carelessness characterise the inexcusable nature of their error. Therefore, their request to cancel the sale on this basis is dismissed," the judges said in their decision.

The court also ruled that the antiquities dealer, who is not an expert in African art, did not deceive them on the price, and that the couple was not owed any money.

As proof of his honesty, the dealer had initially offered to pay the couple the value of €300,000, the mask’s starting price at auction. But the couple’s children refused and chose to sue the dealer for the full amount instead.

Auctioneers described the object as an “extremely rare 19th-century mask, belonging to a secret society of the Fang people in Gabon,” an ethnic Bantu group.

Only about 10 such masks are believed to still exist. One auction house told French media that this type of mask was "even rarer than a Leonardo da Vinci painting."

The couple, who are in their 80s and retired, sold the mask and other artefacts found in their second home in the Gard region of southern France. Most of the items, including the mask, had belonged to an ancestor who was once a colonial governor in Africa.

Their lawyer said his clients were astounded by the court’s rejection and are considering appealing the ruling.

The court also rejected a second motion from Gabon’s government to cancel the sale and return the mask to its country of origin, saying there wasn’t sufficient information about how the mask ended up in France in the first place to rule in their favor.

At the outset of the trial in Alès, two lawyers representing the transitional government of Gabon had filed a motion to "achieve the successive cancellation of sales of this mask, its repatriation and the consignment of funds." — Euronews