The Customs Division has seized two bowsers as part of its fight against contraband fuel.
In a statement, it said that initially it seized a fuel bowser from Zejtun and some time later it seized another marked to be carrying water but holding 10,000 litres of diesel from Xrobb l-Ghagin.
Both bowers belong to the same owner.
Further investigations led to the discovery of three 1,000-litre plastic tanks full of diesel from a garage in Zejtun.
Another three empty tanks were found at another garage in Zejtun. The smell of diesel which was spead on the ground dominated, the division said.
Investigations are continuing by the division and the Economic Crime Unit of the police.