The resources authority received a surge of complaints about the quality of diesel over the past days and is about to start legal proceedings against a petrol station owner over fuel that was allegedly tampered with.

A spokesman for the Malta Resources Authority confirmed it had seen a surge in complaints over inferior quality diesel after it said earlier this week it had instituted four cases against four petrol station owners when random tests showed the fuel they were selling was not according to legal specifications.

The MRA would not name the petrol stations, although it is believed two are located in Malta and two in Gozo.

When contacted, a number of mechanics said they had come across an unusual number of problems with diesel pumps, which could be the result of tampered-with fuel.

However, one diesel specialist said the situation was better when compared to 2009 when they had seen a surge in complaints about leaking diesel pumps.

Another mechanic cautioned that leaks in diesel pumps was not necessarily caused by “dirty diesel” but could be the result of the type of low sulphur fuel Enemalta started importing in 2009 and which could badly affect older diesel engines.

This explanation was similar to the one given in 2009 by Enemalta, in reaction to complaints by motorists that the diesel pumps in their cars had sprung leaks.

It had said that, because of an EU directive, it had to start importing low sulphur diesel and that this could have been the cause of rubber seals in the diesel pumps contracting, resulting in leaks. If the rubber of the seals is not tough enough, the rubber can crack, causing a leak.