A Nigerian national was among five people arrested in separate raids in Pathum Thani and Bangkok that netted more than 10 kilogrammes of crystal methamphetamine and some 40,000 speed pills.
The suspects - Satang Lamsamcharoensap, 42, Arthit Maneethong, 63, Thawet Panang, 51, and Yupin Sirisopha, 40 - appeared at a police press conference at the Narcotics Suppression Bureau Wednesday.
Seized from them were 10kg of crystal meth, known as ya ice, 41,800 methamphetamine pills in 20 bundles, a taxi, a 9mm Colt pistol and six mobile phones.
NSB chief Rawat Klinkasorn alleged the arrests came after investigators learned Mr Satang had planned to sell 10kg of ya ice for 10 million baht. Officers disguised as potential buyers then contacted the man. Mr Satang and Mr Arthi allegedly later contacted Mr Thawet and Ms Yuphin to obtain the drugs before returning to a room at the Asia Airport Hotel in Pathum Thani's Lam Luk Ka district, where they were caught.
Another police team closely monitored the two other suspects and arrested them at the Thaweethong 3 housing estate in Bangkok's Nong Khaem district, said Pol Lt Gen Rewat.
During the interrogation, Mr Arthit, operator of a used-car lot, told police his business was operating at a loss, which forced him to sell illicit drugs, police claimed. Mr Thawet reportedly confessed that he got involved in the drug trade as it offered handsome profits.
In another raid, Arinze Chidi, 34, a Nigerian national, was apprehended after police found 670 grammes of ya ice at an apartment in the Prawet area of Bangkok.
The crystal meth was found in small plastic bags hidden in his closed-circuit television camera during a police raid on his room on Jan 19.
A source said the drugs seized from the two cases had a face value of some 19 million baht.