Police are hunting for the thieves who stole the fuel from a site in Vilhelmina, northern Sweden.
The culprits managed to manipulate the pump operated by IDS (International Diesel Service) to steal the fuel, according to police in Umeå.
It was an automatic pump, and the theft was only discovered when a reading was done remotely in the company’s Stockholm main office, showing that 40,000 litres of diesel had been stolen.
“It’s not clear how it happened but it seems they managed to manipulate the filling station. Many others have used the pump afterwards so it is hard to establish a physical track,” Michael Karlsson, duty officer with Umeå police, told local newspaper Västerbottens-Kurien.
Technicians from IDS have inspected the automatic machine to establish how the crime was carried out.
“The timing of the theft is unclear,” said Michael Liljenberg, also of Umeå police, who appealed for witnesses to come forward with any additional information about the crime.
“For these kinds of crimes to be solved it requires close observation or camera surveillance,” he added.