Trading standards officials have launched an investigation into claims that forecourts have been selling contaminated petrol after hundreds of motorists have complained that their cars have suddenly broken down after filling up.
Drivers in the south-east have reported that their vehicles have suffered juddering, misfiring and a loss of power.
Forecourts at supermarket stores Tesco and Morrisons have so far been the focus of attention, although the problem could be more widespread.
Ian Hillier, petroleum spokesman for the Trading Standards Institute, said: “Officers are investigating these complaints and samples of fuel from some of the affected cars are currently being tested for contamination, as are the contents of the pumps from which petrol was drawn. The problem appears to be restricted to unleaded petrol.”