The police have detained four men in connection with abusing the benefits of subsidised diesel fuel during a raid on a heavy vehicle repair workshop at Jalan Putra in Mergong Tengah here.

Seized from the suspects were 20,000 litres of fuel, believed to be subsidised diesel worth RM40,000.

Also confiscated were a six-tonne lorry, four-wheel drive (4WD) vehicle used to transport the diesel and three storage tanks worth a total of RM145,000.

Langkawi Region One Marine Police Force (PPM) Commanding Officer ASP Rodzi Abu Hassan said the raid yesterday was conducted after a four-hour surveillance which began at 9am.

He said initial investigations revealed that the workshop was used to store the subsidised fuel.

"Our intelligence information indicated the syndicate bought the subsidised fuel at petrol stations in the Kota Setar and Kuala Kedah districts and stored it in the workshop before smuggling it out of the country," he told reporters here today.

He said the suspects, aged between 32 and 63, comprised the workshop owner, pump operator, lorry driver and 4WD vehicle driver.

"We found many heavy vehicles going in and out of the workshop compound, but during the raid, there was only a lorry and a 4WD vehicle used to pump in fuel into the main tank. The fuel tank of the 4WD vehicle was found to have been modified.

He said this was the fifth success of the Region One PPM, in its efforts to combat diesel smuggling, involving Kuala Perlis, Kuala Kedah and Langkawi.