Weighing scales at 70 per cent of jewellers are not properly calibrated, The Sunday Times of Malta has learnt.

Figures obtained from the Metrology Department, responsible for inspecting weighing instruments, show that of 86 jewellers inspected between 2011 and 2014, only 12 were correctly weighing precious metals and stones.

The authority would not say how much the weighing scales were off by nor did they confirm whether any signs of tampering had been discovered. A list of which jewellers found with incorrectly calibrated scales was not provided either.

The authority did say, however, that nearly three-quarters were “favouring buyers”.

Francis Farrugia, who heads the department, said that 54 out of the 74 uncalibrated scales were giving readings which benefited the buyer rather than the jeweller.

Tony Vella, whose St Paul’s Bay jewellery shop buys and sells gold, said his scales were not calibrated properly when the authority inspected them. Although the difference in weight was minute, he still estimates that he may have lost hundreds of euros over the past three years.

“I have people who come and bring me gold and silver jewellery which they want to sell. I’ve been weighing half a gram off per 10 grams. That still amounts to quite a figure,” he said.

Mr Farrugia said that determining the exact amount the scales were out by was a complex exercise which could not be given in a short time.

He said the authority was still inspecting the findings; however, an exact breakdown of when the inspections were carried out was not provided.

Earlier this month, this newspaper had reported how nearly half the petrol stations on the island were giving motorists less fuel that they were paying for.

Inspections by the same authority had found that some petrol stations were dispensing as much as 350ml less per 20 litres, around two per cent of every fuel top up.

Although none of the pumps was found to have been tampered with, the authority estimated that consumers were being short-changed around €1.1 million worth of fuel every year.

Jewellers and petrol stations, however, were not the only ones with poorly calibrated equipment. The authority said that 1,701 inspections were carried out on weighing scales in the past four years. More than 340 were found to be giving incorrect readings. Again, an exact breakdown was not given; however, the authority said that around three quarters of the scales were favouring buyers.

Asked about these figures, Mr Farrugia said it was based on a random sample taken from all of the tests conducted.

After jewellers, butchers had the worst weighing accuracy. The figures show that more than a quarter were not selling the right amount of meat.

Supermarkets also had a problem with their scales, with 13 per cent incorrectly weighing produce. The same was true of the scales used to weigh suitcases at Malta International Airport. Passengers are often charged extra for overweight luggage.

Several different businesses were also found to not be weighing items incorrectly. Mr Farrugia said the Metrology Department had found around 10 per cent of minimarkets, grocers and hawkers had poorly calibrated scales.

Many turn to the Pitkali farmers’ market to purchase their fruit and vegetables on the cheap. And, according to the authorities, these were extra cheap, as all 11 scales tested there were giving buyers more than they paid for.

Out of 33 fishmongers inspected six were found to have wrongly calibrated scales.

All the confectionaries, Liquigas providers, freight distributors and ice distributors inspected had no problems with their scales.

Post offices were also inspected but only three of the scales used to weigh packages were found to be off out of 120 inspections.