Police found three dozen macaque monkeys dead in the back of a truck, and arrested two men who admitted to drugging the animals and stuffing them into sacks in order to smuggle them, authorities said Sunday.
Police stopped the truck at a checkpoint in Thailand's northeastern Amnat Charoen province. An inspection revealed the truck was carrying 65 monkeys, known as crab-eating macaques, of which 36 were dead, police Capt. Pitak Chompupeun.
The truck's driver and passenger were both arrested and face up to four years in prison on smuggling and related charges.
The two men told investigators they had stolen the monkeys from a national park and admitted to feeding them food laced with tranquilizers, which may have been a factor in the deaths, Pitak said.
Their plan was to sell the monkeys to black market traders who pay about 2,000 baht (US$55, €45) per animal, the men told police.
The surviving monkeys were returned to their national park.