Dried bull's blood has been used for centuries as a fining agent to clear the wine.

French authorities recently seized 100,000 suspect bottles after investigations at 14 vineyards in the Côtes du Rhône area.

Bottles marked VDQS, or vins de qualité supérieur - the French term for good quality table wines - are the ones most at risk of containing the product.

Tesco, Britain's biggest supermarket chain, said it had not stocked VDQS wines for about five years.

Asda said it was monitoring the situation to see if any other wines were affected but had checked its stocks and was sure it did not sell the wine.

Sainsbury's said that cows' blood had been excluded from their specifications for wine suppliers since the ban two years ago.

First Quench, Britain's biggest off-licence chain which owns about 3,000 stores nationwide under names such as Thresher, Victoria Wines, Bottoms Up and Wine Rack, assured customers that it did not stock any bottles of the affected wines.

Off-licences say there is nothing to fear

Its senior wine buyer said that wines using the additive were generally regarded as down-market and would not be sold in First Quench shops.

"This red wine would be at the bottom end of the market and supplies in this country would be limited. It would be unlikely that it would be on sale in major retailers in the UK as our wine buyers would always buy from the quality end of the market," he said.

The real problem for consumers in the UK, he added, might be for those travelling across the Channel on "booze-cruises" to stock up on cheap French wine.

Ban flouted

But one French table wine exporter said rogue bottles could have made their way across the English Channel. "It is probable that, if the ban had been flouted for the past two years, several million bottles of the vetoed product have crossed to Britain," said Jean Pistonier.

However, Gerard Bedos, a fraud investigator, said that consumers have little to fear.

"It is important to stress that just because blood has been added to wine, it doesn't mean the blood was infected with BSE," he said. "The process was banned as a precautionary measure."