Narcotics police seized 1.2 tonnes of crystal methamphetamine, known as ice, and a convoy of of three vehicles at a house in Na Mom district, Songkhla province.
Narcotics Control Board secretary-general Wichai Chaimongkol released details on Monday.
He said the raid followed intelligence reports that a large quantity of drugs was being trafficked from the northern border to the South, for storage before being smuggled into Malaysia.
On May 24, the Insee 19 special operations team staked out a house at Moo 5 village in tambon Thung Khamin of Na Mom district before dawn. They raided the premises after seeing two pickup trucks and a car arrive there.
A search of the house found bags containing 900 kilogrammes of crystal meth. A search of the three vehicles found bags containing another 300kg of ice on the two pickups. All were impounded.
The occupants had already fled the property. There were no arrests.
Mr Wichai said the ONCB had informed the Narcotics Crime Investigation Department of Malaysia of the seizure of the drugs, so that it could investigate further and identify the intended recipients.