A man was arrested with 1.49 tonnes of crystal meth and 91 kilogrammes of ketamine at a warehouse in Pathum Thani province.
The Narcotics Control Board said on Wednesday that Suwit Prom-on, 26, was arrested with the drugs, a gun and ammunition at a warehouse in Pathum Thani in the morning of Tuesday.
The arrest came after a tip-off from local residents and a subsequent investigation.
Mr Suwit and another man arrived at the warehouse in tambon Bang Luang of Muang district at about 2am on Tuesday. Officials arrested Mr Suwit while the other suspect fled. Officials found 100kg of crystal meth or "ice" and 91kg of ketamine in their Honda Freed vehicle.
A search of the warehouse produced 1.39 tonnes of "ice" hidden in a false compartment in the back of a six-wheeled lorry, but a similar compartment in another six-wheeler was empty.
The board said that the suspect rented the warehouse to store and pack narcotics for export to Australia, Indonesia, Japan, Malaysia and South Korea. The drugs were smuggled into the country from a neighbouring country.
Officials were expanding the investigation to find other culprits.
