The pangolins were said to worth at least Bt615,000.
The unidentified boatman, who attempting to smuggle the protected species from Laos to Thailand's Ban Chaem Pong border point in Tambon Lai Ngao, escaped arrest by swimming away in the darkness, said Navy Captain Wuthichai Phucharoenyot, chief of Chiang Rai-based Mekong patrol unit.
The smuggling of pangolins is a violation of the Wild Animal Reservation and Protection Act 1992, punishable with up to Bt40,000 in fines and four years in jail. The case was passed onto the police to investigate further to identify the boat owner and arrest those involved.