French wine growers have fallen victim to a “mafia” which is systematically stealing entire crops of grapes.

The criminals strip acres of vines bare and, overnight, take what can represent a year’s work for the farmer, which can mean financial ruin for the grower as agricultural insurance tends not to cover raw fruit.

Similar crimes have taken place in Germany and the US, and many believe the thieves are professionals working in the industry.

However, a French detective from a specialist scientific unit assigned to investigate said he feared “a wine mafia gang” was targeting “some of the best grapes”.

He added: “We are undoubtedly dealing with the kind of upmarket criminals who steal old master paintings and antiques to order.”