(Wine-Searcher) - A producer has been accused of blending inferior wines and passing them off as Chablis in a decade-long scam.

The head of a French wine company has been arrested and jailed after an alleged scam was uncovered, involving inferior wine being labeled and sold as Chablis.

Jean-Claude Fromont, the CEO of Maison Fromont, in Ligny-le-Châtel, Yonne, was remanded in custody over the alleged fraud.

"He is accused of using wines from the south to blend with Chablis and calling them 'Chablis'," the Deputy-Prosecutor, Frédérique Olivaux told regional daily newspaper Le Journal du Centre.

The non-Chablis wines are believed to have come from Provence and the Rhône Valley, where Maison Fromont also has vineyards.

The investigation began six months ago after the tax department discovered irregularities. Customs and fraud investigators then became involved as well.

"The first elements of the investigation reveal that the fraud – the magnitude of which is not yet known – lasted 10 years," said Olivaux, who added that the damage done was major both in terms of volume and the appellation's reputation.

Fromont's cellar master and a freight company were also investigated, but not jailed.

Chablis winegrowers were in shock over the news.

"If this fraud charge turns out to be true, it would be extremely serious for the image of Chablis. I am really frightened," Frédéric Guégen, president of the Federation of Defense of the Appellation Chablis (FDAC) said.

"Let the investigators continue their investigations but, if fraud is proven, and it has been going on for a decade, that would mean it involves substantial volumes." He said it was unfortunate that one producer could do such potential damage to the appellation's image.

Chablis wines are made exclusively from Chardonnay and are famed for their minerality and crisp acidity. Almost 700 producers make around 40 million bottles of wine each year, across the grand cru, premier cru, Chablis and Petit Chablis categories, of which 70 percent are exported.