The news that George and Amal Clooney had bought a vineyard in the small town of Brignoles in Provence had locals dreaming of a glamorous future.

Winemakers envisaged the actor becoming an ambassador for their rosés, while Didier Brémond, the mayor, struggled to overcome his delight at the sight of American television crews filing past the town hall.

“With George Clooney, we are in a new dimension,” he said recently.

Brémond may have spoken too soon as it has emerged that the Clooneys’ purchase of the Domaine du Canadel is being challenged before the courts by another buyer claiming to have been gazumped, a practice banned under French law.

There is no suggestion that the Clooneys did anything unlawful, or indeed knew of the alleged gazumping. A spokesman for the prosecution service in Draguignan confirmed that a lawsuit had been registered but added that it would be months before it is heard.

Guy Azzari, the buyer’s lawyer, alleges his client had agreed a price of $7.2 million in August for the six-bedroom 18th-century bastide set in 425 acres that include woodland, an olive grove, a vineyard and an ornamental lake.

“With George Clooney, we are in a new dimension.”

Azzari claims a signed offer had been accepted before the sellers, a retired Australian couple, upped their asking price to $7.5 million before backing out of the deal.

He said he had filed a lawsuit contesting the sale of the vineyard to the Clooneys, adding that it would take between “one and four years” for the case to come before the civil court in nearby Draguignan. Azzari said that in the meantime there would be “uncertainty over the property” and that the Clooneys’ purchase could be reversed.

Under French property law, vendors and buyers sign a binding preliminary contract after agreeing on a price. A vendor who pulls out of the sale after signing the contract has to pay a fee that is often between 5 and 10 percent of the agreed house price.

Azzari did not say whether such a contract had been signed in the case of Domaine du Canadel. The legal wrangles have punctured the enthusiasm which had greeted the arrival of the actor and his British wife, which was announced by Brémond himself.

“When you have someone like George Clooney who is buying in your district, you can only congratulate yourself,” he said. His delight was understandable. Neighboring districts in Provence have witnessed an influx of celebrities and tycoons in recent years, most of them intent on making the rosé wines that have become highly fashionable.

The Hollywood producer George Lucas owns Château Margüi in Chateauvert down the road, and Brad Pitt and Angelina Jolie have the Domaine du Miraval in Correns, which is also about half an hour’s drive away. Sir James and Lady Dyson have another vineyard, the Domaine des Rabelles, about an hour to the north. Joachim Splichal, the German celebrity chef, has a vineyard in Brignoles — but he is not quite in the same league as George Clooney.

Eric Lambert, head of the local wine-making union, said he had no idea whether the Clooneys intended to make their own wines, like Pitt and Jolie, Lucas and the Dysons. Until now, the Domaine du Canadel’s grapes have always been mixed up with those from surrounding vineyards in the local cooperative, he said.

Either way, Clooney’s presence would be a boost, according to Lambert. “What is sure is that he is going to become a new ambassador,” he said recently.

Now it may not be quite as sure as he thought.