Over half of the 147 tigers confiscated from the Tiger Temple - a tourist attraction where visitors could take selfies with the big cats - have died in captivity within the last three years, local media reported.
The Wat Pha Luang Ta Bua or Tiger Temple, located west of Bangkok, promoted itself as a wildlife sanctuary that charged visitors admission to interact with the animals.
However, just three years ago, the government removed 147 tigers after the site was linked to wildlife trafficking.
Rescuers took the tigers to two state-run sanctuaries where many were found to be at risk of contracting canine distemper virus, Sky News reported.
NIGHTMARE CREATURE HAD EGG-SHAPED EYES, SWISS ARMY KNIFE HEAD, AND A BUTT SHIELD
"When we took the tigers in, we noted that they had no immune system due to inbreeding," the deputy director-general, Prakit Vongsrivattanakul of Thailand's department of national parks, wildlife and plant conservation (DNP), told the state-owned broadcaster MCOT. "We treated them as symptoms came up," he added.
Prakit didn't give a number for exactly how many of the tigers have perished, although Thai PBS reported the numbers to be 86 out of the 147 confiscated animals, most of which were of the Siberian breed.
Many of the tigers have been dropping dead one by one since May 2016, the Bangkok Post reported.
The tiger temple had been promoted as a wildlife sanctuary, but it was investigated due to suspicions by the government regarding links to animal abuse and wildlife trafficking.
HUGE ICE AGE KANGAROO HAD UNIQUE LINK TO GIANT PANDAS, RESEARCHERS REVEAL
Many of its monks were accused of illegally breeding tigers, while visitors reported that some of the tigers appeared drugged, Sky News reported. The temple denied allegations of abuse and trafficking.
During the raid three years ago, Thai officials reported finding 40 dead cubs in a freezer along with 20 jars full of baby tigers and organs. A monk was reported to have tried escaping the temple in a truck carrying over 700 vials of tiger skin and teeth hidden in a suitcase.
CLICK HERE TO GET THE FOX NEWS APP
"I am quite shocked," Teunchai Noochdumrong, the director of the government's wildlife conservation office, said in 2016. "We all have heard concerns and allegations about this temple. I would never have thought they would be so blatant."
The Siberian tiger is the largest of the tigers and considered a critically endangered species whose threats to survival include poaching and habitat loss, experts have said.