Thai authorities arrested a man on Friday after 16 tiger cubs in plastic crates were found in the back of his truck during a routine check in a northeastern province near the border with Laos.

Authorities stopped the truck after attempting to avoid a police checkpoint, Business Standard reports. The driver told the police he had been paid 15,000 baht ($500) to transport the cubs through the border and claimed he was unaware of who owned the animals.

“He said he only talked to them on the telephone, not in person,” Lieutenant Colonel Kusol Pongbunchan, chief investigator of the local district police told AFP.

The 52-year old man faces a possible four-year jail term or a fine of 40,000 baht ($1,300) for illegal possession and trafficking of endangered species.

Thailand is an international smuggling hub for tiger body parts, highly valued for their reputed medicinal properties. The population of tigers worldwide has dwindled to 3,200 from approximately 100,000 a century ago. Thailand is one of 13 countries which hosts reserves for the endangered cats.