Two men have been arrested for possession of 285 kilogrammes of pure crystal methamphetamine, worth more than 600 million baht, police said.
Police chief Chakthip Chaijinda said yesterday Chang Kim Sui and Lim Yean Hooi, both Malaysian nationals, were busted by police attached to the Narcotics Suppression Bureau at the Thai-Malaysian border in the Sadao district of Songkhla.
He was speaking yesterday as he announced the arrest of the suspects.
He did not say when the arrests were made.
The duo were caught as they were driving through Sadao checkpoint where they were stopped by authorities, police said.
A search of their vehicles found seven bags containing a total of 285kg of crystal methamphetamine, police said.
Police seized the drugs and two cars from the suspects as evidence, the national police chief said.
Pol Gen Chakthip said Thai intelligence agencies were tipped off by Malaysian authorities that drug runners would attempt to smuggle drugs from Thailand into Malaysia.
"It was one of the country's largest drug busts thanks to the cooperation of Malaysian authorities," Pol Gen Chakthip said.
The value of the seized drugs, which were pure, would likely increase had they been smuggled into a third country, he said, adding the seized drugs have an estimated street value of more than 600 million baht.
Police believe the suspects are not linked to a drug ring arrested last week on a train that was heading to Malaysia.
Pol Gen Chakthip said he has ordered police to step up suppression efforts to stem the flow of drugs through the country's borders during Songkran festivities.