A stray dog has charmed locals as he worked as an unofficial security guard at a fuel station in Thailand.

Namtarn, 6, became an online sensation for dutifully inspecting oncoming vehicles at the PTT petrol station in Pathum Thani province.

Donning a blue floral vest and an employee ID, the canine takes his post next to a fuel pump, greeting motorists who come to refill their cars and barking to warn drivers when they are too loud.

Pump attendant Phanomchai Khamtha said Namtarn has been staying at the station for around four years.

Station owner Theeraphong Labpholtaweeying said he decided to adopt the pooch several years ago as he felt sorry for it wandering around without a master.

He said: 'I gave the dog an employee card because he was so friendly and loved approaching people. That way, everyone would know who he belonged to if he ever went missing. Namtarn is paid weekly in food expenses, and the staff make sure he's well cared for.'