(PRI) - At least 7 metric tons of grapes were stolen in the dead of night from vineyards in France's prime wine-growing region of Bordeaux after a yield hit by poor weather, police say.

Three vineyards have had grapes and even whole vines stolen since mid-September, police told AFP on Wednesday.

They said about 6.5 metric tons of grapes disappeared from a vineyard in Génissac near the world-famous Saint Émilion region, adding that the theft was clearly committed by professional vintners.

Between 600 and 700 kilograms (1,300 and 1,500 pounds) of grapes were stolen from a vineyard in Pomerol, which produces top quality reds.

Thieves also uprooted 500 vines from a vineyard in nearby Montagne, police said.

A fourth grape robbery took place in Lalande-de-Pomerol, according to a local press report.

Thieves making away with grapes is not a new phenomenon but it has surged this year apparently because of a disastrous yield. 

"There's a great temptation to help oneself from [the vineyard] next door," an industry expert told AFP on condition of anonymity.