SALT has never been in as much demand.

But analysts at West Yorkshire Trading Standards have found a lack of it where it’s really needed.

Public Analyst Dr Duncan Campbell has spent years trying to reduce salt levels in food, but his investigations into rock salt found a distinct lack of it.

Working with West Yorkshire Trading Standards following a complaint, Dr Campbell analysed a bag of material being sold as rock salt which contained only 23% salt.

Lumps of pure salt – some the size of a table tennis ball – were discovered in the sample.

But the majority of the product’s content was sharp sand and small stones.

A material sold as rock salt for spreading on highways must, by law, be made up of at least 90% salt and contain less than 7.5% insoluble material.

Graham Hebblethwaite, chief officer of the West Yorkshire Trading Standards Service, said: “Even at a time of shortages, such as those we have been seeing recently, consumers have a fundamental right to get what they are paying for.

“Consumers should not have to pay over the odds for products that are either misleading or of a substandard quality.”

The recent bout of cold weather has resulted in a shortage of rock salt. Many suppliers are out of stock and others have been rationing sales or hiking the prices, with 25kg bags selling for up to £8.