Customs rescued 225 live spotted pond turtles worth about Bt1 million from four unclaimed luggage bags at Suvarnabhumi Airport yesterday.
Auychai Kultipmontre, director of the passenger control customs unit, said the baggage was left unattended next to carousel No 18 of the arrival hall in the early morning.
"Officials asked people there who owned these bags but no one came forward," he said.
The "suspicious" bags were then X-rayed.
"They were smuggled in. Normally, importers of such animals must seek and receive clearance from the Department of National Parks, Wildlife and Plant Conservation," he said.
The turtles were handed over to the airport's wildlife quarantine station while officials look further into the case to nail down the offenders.
It is not the first time turtles have been found at the airport.
Last year, on November 6, 423 Geocheleon radiata turtles and 52 spotted pond turtles were nabbed at the airport. Two days later, a Pakistani air passenger was arrested for carrying in 470 spotted pond turtles. On December 10, a Madagascan was caught illegally sneaking 60 radiated tortoises into the country.
Many Thais buy turtles as rare pets or for good luck, as turtles and tortoises are widely associated with long life.
A big spotted pond specimen can fetch up to Bt25,000 (S$967.25).
Veterinarians said a long flight could exhaust the turtles, which are sometimes wrapped in plastic to prevent them from moving and attracting attention from authorities.
Some of them may even succumb to failed health during transit or soon after.