At least eight police forces were said to have stopped investigating motorists who failed to pay for petrol

A rising number of petrol stations are going out of business because police are refusing to investigate drive-off thefts, according to industry leaders.

Figures show that the cost of “bilking” incidents grew by a fifth in the last three months of 2018 following warnings that officers were too busy to track down offenders.

A new analysis shows that petrol stations lost an average of £420 per forecourt between October and December — a rise of 21.4 per cent from the previous three months.

It is feared that motorists are being emboldened into driving off without paying following reports in the autumn that at least eight police forces no longer investigate the crime.

The British Oil Security Syndicate, which compiles a quarterly forecourt crime index, said