Police have arrested a Myanmar man with 100,000 speed pills and seized illegal unprocessed gold, weighing 5,200 grammes, from a Myanmar woman in Chiang Rai.
The suspects were identified as Ong Pia Piao, a 31-year-old man, and Li Wi San, a 30-year-old woman. Both are Myanmar nationals.
The arrest date was undisclosed.
Police say they seized 100,000 amphetamine pills from Ong Pia Piao.
They also confiscated 40 chunks of unprocessed gold, found in 19 sacks weighing about 5.2 kilogrammes and three chunks of unpolished jade, worth about five million baht in total, from Li Wi San.
Chiang Rai provincial police chief Pol Maj Gen Weerawut Niamnoi said the pair were nabbed after authorities heard the drugs would be smuggled into the country along the Mae Sai River in Mae Sai district.
While authorities were lying in wait, Li Wi San appeared with the sacks and a suitcase, crossing an irregular border pass from the Myanmar side.
Police asked to inspect her personal effects and discovered the illegal gold and jade.
Pol Col Songkrit Ontakrai, chief of Mae Sai station, said the arrest of the Myanmar woman alerted the drugs ring to the police operation.
Police later heard the drugs they were after had been hidden inside a house in Moo 10, tambon Mae Sai.
After searching the house, authorities found Ong Pia Piao inside with 100,000 speed pills hidden in a backpack. Under questioning, he said he was only the courier.
The drugs were due to be delivered to dealers. Ong Pia Piao was charged with possession of amphetamine pills for sale.
Police also charged Li Wi San with smuggling gold into the country without paying tax. She is being detained for further questioning.