(Telegraph) - Deaths of four people in a flash flood in Italy's Prosecco-producing region sparks debate about whether expanding vineyards are to blame.

Italy's picturesque Prosecco-producing region has been plunged into bitter acrimony amid accusations that its expanding vineyards were responsible for creating a terrifying flash flood that claimed the lives of four people.

Critics say that the clearing of woodland to make way for new vineyards, as sales of Prosecco boom both in Italy and abroad, have made the region's steep slopes more unstable and less able to absorb heavy rainfall.

They claim the more intensive cultivation contributed to the flood on Saturday night, when a violent storm caused the Lierza river to burst its bank, sending a torrent of water through a local beauty spot, a 17th century mill, the Molinetto della Croda.

The flash flood hit a local banquet, sweeping away cars, marquees and people.

Four men were swept away, with some of the bodies found nearly a mile downriver, while eight other people were injured.

Prosecutors in the nearby city of Treviso have opened an investigation, saying they could bring charges of manslaughter and culpable environmental damage.

They will call for information from engineers and geologists "to understand the causes of the disaster," said Laura Reale, a prosecutor.

As the injured recover in hospital and locals clean up the mess left by the torrent of muddy water, a rancorous debate has broken out over whether the intensive cultivation of the area for Prosecco grapes is to blame for the disaster.