Thanaphat Paravech, 27, a teacher hired on a temporary contract at a school in Ubon Ratchathani's Na Tan district, and his four alleged accomplices were caught after police gave chase and fired shots at their pickup truck's tyres on the Khon Kaen-Chiang Yuen road in Muang district of Khon Kaen on Sunday.
The four others were identified as Prasarn Saengdaeng, Samran Saengdaeng, Rangsi Chuekhamchan and Thepnapa Natvej. Police say they seized 23,900 speed pills and six mobile phones from them.
Mr Thanaphat is the son of a border patrol police officer, Khon Kaen police chief Pol Maj Gen Chob Khisalang said.
The suspects allegedly received drugs from a network run jointly by a woman known as "Jae Pen" of Ubon Ratchathani's Khemarat district and a Lao woman known as Ms Oon.