Eight TIGERS and a lioness, belonging to a Russian traveling circus, have died during a 20-hour journey across Siberia in an enclosed, heated truck.
The animals were found dead when they arrived early on Tuesday in the city of Yakutsk, where they had been due to perform in holiday shows.
Local police are investigating whether animals were poisoned by carbon monoxide exhaust fumes.
Several other circus animals, including a dog in the same truck, survived.
A circus employee said the truck should have been better ventilated and opened every two hours.
According to reports, the circus team who should have been looking after the animals were instead found drinking.
The animals were part of the private "Mechta" circus based in the southern city of Krasnodar.
A World Wildlife Fund official in Russia says that while the transportation of animals is strictly controlled in circuses which receive state funding in Russia, private ones are not sufficiently regulated.