The suspects, identified as Ley Binh, 40, and Nguyen Wan Tung, 29, were apprehended at 10pm after a tip-off to police that suspicious persons were transporting illegal items onto a bus which stopped at Phitsanulok bus station.
After a search, officers found the smoked tiger body parts in the pair's large luggage bag which was loaded in the luggage compartment under the bus.
Protected Area Regional Office 11 (Phitsanulok) director Nipon Jamnongsirisak, who inspected the carcass at the precinct on Thursday, said the three-metre-long complete carcass (head to tail) was a 200-kilogram male tiger aged about 15-20 years old.
All parts of the animal had been well cut and smoked and could fetch up to Bt2 million if sold in other country, he said, adding that there was no skin or internal organs.
Nipon said he had reported this case to the National Parks Department to have experts inspect the 23 body parts. The tiger carcass would be kept for investigation for about one month, after which it would be destroyed, a police source said.
During the interrogation at the Muang Phitsanulok precinct, the pair initially told police that they bought the carcass from a compatriot in Tak on October 4 for only Bt30,000.
They were transporting the items from Mae Sot to Khon Kaen before travelling onward to Nong Khai where they would cross the border to Laos and then Vietnam.
They face three charges of having the carcass of a protected wildlife animal in their possession, wildlife trading, and concealing a wildlife carcass for later distribution.
Besides the tiger carcass, police also seized two bags containing a total of two kilograms of Agarwood pieces from the suspects.
Muang Phitsanulok superintendent Pol Colonel Songpol Sangkasem said he would extend the investigation to find accomplices and check the immigration status of the suspects to see of any other charges should be filed.