Hail storms in Bordeaux last week have caused greater damage than first thought, threatening up to 30% of the 2009 grape harvest in some of the region's most iconic wine areas.

Worst affected have been the southern Medoc and Margaux, Cotes de Bourg, Cotes de Blaye, Entre deux Mers and Saint Emilion.

"4,000 hectares were affected in St Emilion, 2,000 hectares very badly," said Alain Vauhtier at Chateau Ausone in St Emilion, adding: "500 hectares were destroyed."

Among the chateaux affected across the region have been Chateau Palmer, Chateau de Fonbel, Chateau Trottevieille and Chateau Pavie.