Thai police have seized a vast haul of methamphetamine worth $45m (£35m) packed into large container bags.
The 14 million orange pills, known as “yaba” or “crazy drug”, were bound for Malaysia when they were intercepted in Autthaya province, north of Bangkok.
The lawless Shan State, in northeast Myanmar, is known for the production of opium and heroin and is under the control of an ethnic Wa militia force.
Crazy drug is associated with hallucinations, psychosis and paranoia and is highly addictive.
Three Thai nationals were arrested in connection with the drugs, police said.
Police Lieutenant General Sommai Kongvisaisuk said: “It gets distributed to Europe, America, Australia, Japan, Singapore and Korea and will make a lot of money.”
The surging trade in narcotics has had a destabilising effect on Myanmar’s politics as local and international groups fight control of smuggling routes.
Production and trafficking of methamphetamine in southeast Asia has reached “alarming levels”, according to a UN Office of Drugs and Crime report.