Klao, a 50-year-old elephant lies dead with its tusks were taken off on the ground in Ayutthaya province, central Thailand.
Poachers have killed and sawed the tusks off a 50-year-old elephant that performed in Thai royal processions and was featured in Oliver Stone's 2004 movie "Alexander," the manager of the conservation center where the animal was kept said on Friday.
Laithongrian Meephan of the Ayutthaya Elephant Palace and Royal Kraal said the elephant was found dead on Friday morning. Poachers had apparently poisoned it before cutting off its tusks.
The center breeds and trains elephants, and also serves as a retirement home for aging beasts.
Some of them take part in ceremonial shows for members of Thailand's royal family and tourists in Ayutthaya, the country's ancient capital.
Laithongrian said the elephant, named Klao, was used in some scenes of the film "Alexander," which starred Colin Farrell and Angelina Jolie.
The wildlife trade monitoring network TRAFFIC said in a report earlier this month that "Thailand has the unenviable reputation as home to one of the world's largest unregulated ivory markets."
Elephants are the de facto national animal and were once featured on the Thai flag. TRAFFIC estimates that Thailand has a population of 2,500 to 3,200 Asian elephants in the wild, and cites government statistics that another 4,169 were held in captivity in 2012.
Their numbers have decreased over recent decades and expanding human settlements have shrunk their natural habitat. The beasts once were used overwhelmingly for logging, but deforestation and a consequent ban on most logging has led to many elephants now being used as tourist attractions.
TRAFFIC said one reason that Thailand is a major smuggling point for ivory poached from African elephants is that a 75-year-old law permits the legal trade of ivory from domesticated Asian elephants inside Thailand, though the origin of retail ivory is seldom checked.
"Monitoring of Bangkok's domestic ivory market by TRAFFIC reveals a near trebling of the number of ivory items for sale in the past 18 months and a steep rise in the number of retail outlets selling ivory in Thailand's capital city," it said.
The group said that at least 20,000 African elephants were killed in 2013 to meet the heavy demand for ivory from Asia, and more than 13 tons of African elephant ivory have been seized inside, or headed to, Thailand since 2008.