Police say they have arrested suspects in three cases and seized illegal drugs worth about 300 million baht in the past three days.
Pol Maj Gen Surapol Tuanthong, deputy chief of the Office of Narcotics Control Board (ONCB), announced the arrests at a press conference on Monday.
He said a man arrested with one million methamphetamine pills, or yaba, in his possession was a member of a drug gang operating in Klong Prem prison.
Police had been following the activities of Warawut Chai-anich, 25, for a while and they moved on him after receiving credible information that he was about to move the drugs from Ratchaburi province to Bangkok.
Police set up a checkpoint near Navanakorn industrial estate and found the drugs hidden in his car. He admitted to have been working for a drug dealer serving time in Klong Prem prison.
In the second bust, an Iranian national was arrested with 1,300 grammes of liquid methamphetamine which had been poured into an empty wine bottle. The liquid could have been used to make about two kilogrammes of crystal methamphetamine, or ice.
The arrest of Mahmood Pacchawadee, 56, was due to collaboration with the United States Drug Enforcement Administration (DEA) based in Thailand. Pol Maj Gen Surapol said the DEA advised the police to monitor the movements of the suspect, who is a member of an Iranian drug gang, Pol Maj Gen Surapol said.
He was trapped in a sting operation on Monday and arrested with the drugs in his possession. The ONCB deputy chief said the suspect admitted to having smuggled drugs into Thailand several times, usually in liquid form concealed in wine bottles.
In the third bust, a Thai woman, Saithan Sae-Lim, 39, was apprehended at Suvarnabhumi airport with three kilogrammes of crystal methamphetamine after arriving from overseas.
Maj Gen Surapol said they were tipped off by a source that the suspect was bringing the drugs into the country. He did not say which country the suspect brought the drugs from.
The drugs were found concealed inside the lining of her bag.