Drug suppression officials in Thailand have seized 11 kilogrammes of crystal methamphetamine following the seizure of 9kg of the drug from two Chinese men by Hong Kong customs officials on May 20.
The Hong Kong shipment was hidden inside picture frames in a cargo container aboard a vessel that arrived from Thailand.
Office of the Narcotics Control Board director-general Wichai Chaimongkol said on Tuesday that an expanded investigation had led to the seizure of another 11kg of crystal meth in Thailand.
On May 29, officials went to an international cargo x-ray centre at Suvarnabhumi airport.
Five picture frames similar to those seized in Hong Kong were found in a container about to be shipped to Hong Kong.
Nine plastic bags, each containing 1kg of crystal meth, or ice, were found hidden in the frames.
The same day, officials searched an international shipping company in Soi Phetchaburi 17.
They seized another 2kg of crystal meth hidden in amplifiers which were about to be sent to the Philippines along with other cargo.
Mr Wichai said cooperation between the ONCB and Hong Kong customs authorities had led to several past seizures of drugs being smuggled by sea.
Narcotics control officials find crystal meth hidden in these five picture frames, at an outbound cargo warehouse at Suvarnabhumi airport in Samut Prakan province on May 29. (Photo supplied)