Four brothers from Żurrieq were ordered to pay a fine of €10,000 after diesel with sulphur levels far higher than the legally-established limit was found in the stores of their company.

The case dates back to March 2012, when Malta Resources Authority inspectors paid a visit to Ramel u Żrar Ltd's premises in Dingli Cliffs and took samples of their stored diesel. On such occasions, three batches of samples are taken: one given to the company, another sent for independent testing and a third used in case an additional test is required.

According to the Quality of Fuels Regulations, only diesel fuel with a sulphur content of up to 10 mg/kg could be used. But tests carried out by Saybolt showed a far higher concentration of sulphur in Ramel u Żrar's fuel.

As a result, the company's directors - brothers Gaetano, Manweli, Joseph and Carmelo Abdilla - were accused of failing to exercise due diligence to prevent the commission of an offence, namely the use of fuel which did not conform to specifications.

The court commissioned a test itself, and two samples tested by Italian company Natura srl were found to have 392mg/kg and 386mg/kg of sulphur respectively.

During proceedings, the eldest brother, Gaetano, chose to testify of his own accord.

Mr Abdilla denied ever purchasing contraband diesel, stating that he always bought diesel from two companies - Falzon Service Station and Cassar Petroleum Services Ltd. To back his claim, he provided receipts showing regular purchases from them. However, he said that he was not in a position to state which company supplied the off-spec diesel, pointing out that diesel from both companies ended up mixed together in storage.

The defence, in turn, argued that since the brothers acquired the diesel from a legitimate source, they should not take the blame for a situation which they had no control over. It noted that the brothers had no means to test the diesel themselves.

But Magistrate Consuelo Scerri Herrera said that the issue was not whether the brothers knew that their company's diesel was not up to standard, but whether they actually used it, pointing out that the charge filed against them made no reference to any possible illicit trading.

The simple use of off-spec fuel was already considered a crime, she argued before imposing a fine.