Health inspectors say a product made with dried bull's blood, which has been illegal since a ban imposed during the BSE crisis, may have been used in the winemaking process.

Wine, and about 200kg of blood products, were seized from four production sites in and around Avignon, in the Rhone Valley.

Bull's blood was widely used to clarify wine before bottling until the ban was imposed by the European Union in 1997 as part of measures to fight BSE, or mad cow disease.

In the process, known as fining, the blood would be used to help remove resin and suspended particles - changing wine from cloudy to clear.

Most wine makers now use modern clay-based fining agents to clarify the wine.

But after the seizure in southern France it is feared some smaller wine producers may still be using the blood-based products illegally

The seized wine is being tested to check whether it has been treated with bull's blood.

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Most of the wine seized was table wine, labelled VDQS, and not the renowned Cotes-du-Rhone wine which bears the high-quality AOC (Appellation d'Origine Controlee) label.

Wine producers now fear their industry may be the latest to be hit by a food safety scandal.

Neighbouring Belgium is reeling after cancer causing dioxins were fed to farm animals, and a number of people fell ill after drinking contaminated Coca-Cola.

Philippe Verdier, of the General Union of Cote-du-Rhone Vineyards, said: "The fact that forbidden substances were seized will damage us in terms of image."