An entire street, cellars of apartment blocks and underground car parks have been flooded with wine in a southern French town after a suspected act of sabotage by a shadowy group of "wine terrorists."

Thousands of litres of the tipple poured out of five giant vats of a wine merchant late on Tuesday evening in the Mediterranean port of Sète.

The wine flooded the avenue Maréchal-Juin, the street in front of the wine merchant’s premises, and was several inches deep along a stretch of the road.