Two suspects were arrested and were identified as Adirek Phetkong, a Songkhla resident, and Thossaniyom Trisuwan, from Phatthalung.
Their pickup was stopped at the highway checkpoint in Tambon Liphang.
Police said the two admitted that they were hired to take the drug from Bueng Kan province to Satun for Bt100,000, half of it already paid.