About 20 tonnes of pork was seized from an 18-wheel lorry that crossed the second Thai-Lao Friendship Bridge over the Mekong river to this northeastern border province from Savannakhet province of Laos on Saturday night, according to a media report.
The lorry was stopped at 7.30pm for a search at the animal quarantine centre on the Thai side of the bridge.
Chalongrath Chansongkaew, chief of the animal quarantine centre, said about 20 tonnes of port, worth about 4 million baht, was found in the lorry, which belonged to a transport firm.
Srisuwan, the driver of the lorry, reportedly said he drove the vehicle from Bangkok to Mukdahan on Friday and crossed the Mekong river bridge to Savannakhet, where its container was offloaded.
While in Savannakhet, the truck was loaded with a new container.
On Saturday night, he drove back to the Thai side of the river, where the vehicle was searched and the pork was found in the container.
Mr Srisuwan said he did not know the new container was loaded with smuggled pork.
The truck and the driver were handed over to Muang police station in Mukdahan for legal proceedings, and may face smuggling charges.