It was the overpowering stench and the thick swarm of flies that told Reinet Meyer she had stumbled upon something truly horrific.
Meyer, a senior inspector at the Society for the Prevention of Cruelty to Animals, had been tipped off that lions were being left in tiny cages at the Wag-'n-Bietjie farm, 32km outside Bloemfontein in South Africa's Free State Province.
Knowing that her country's controversial lion breeding industry supplies the appalling international trade in lion bones meant she was expecting the worse. But nothing could prepare her for the grotesque and macabre scene she found inside an anonymous-looking farm shed.
The building was being used as a lion slaughterhouse, and a supervisor and eight workers were stripping the skin and flesh from the fresh carcasses of a group of recently killed lions.
Dead lions, some skinned and others waiting to be skinned, littered the blood-stained floor. A pile of innards and skeletons lay elsewhere inside, while discarded internal body parts were piled high in overflowing black plastic bags on a trailer outside.
Photographs taken by investigators showed a squalid scene of gore. Many are too horrific to be shown.
"It was shocking," Meyer said. "We couldn't believe what was happening. You could smell the blood. The lions got shot in the camp and then were all brought into this one room. The flies were terrible.
"For me, a lion is a stately animal, a kingly animal. Here he is butchered for people just to make money, it's absolutely disgusting."
About 200 yards from the abattoir, two lions were housed in steel transport crates that were too small for them to stand up or turn around in. Meyer said they had been left in the crates without food or water for three days.
She initially thought that one of them was dead because it was not moving.
"The lion was so depressed that it did not move at all. It was totally disgusting that they were kept like this.
"A lion is a wild animal, it wants its freedom but now it's kept in a small cage for three days. It's absolutely deplorable."
A total of 54 lions had been killed at the farm in just two days. They were first shot with tranquiliser darts before being shot dead with a .22-calibre rifle. It is understood the bullets were shot through the ear and directly into the brains because overseas buyers will not pay for damaged skulls.
Some of the lions are believed to have been trucked about 400km to the farm from a "safari park" near Johannesburg.
Remarkably, the workers at Wag-'n-Bietjie are allowed to kill lions. The site, owned by lion breeder Andre Steyn, is one of a series of licensed lion slaughterhouses in South Africa which supply the huge demand for lion bones from South East Asia. South Africa allows 800 captive-bred lion skeletons to be exported each year, but campaigners believe many more are illegally slaughtered to feed the disgusting, but lucrative, trade.
Wag-'n-Bietjie, which calls itself an "eco-farm" that puts "nature first", appears to have been issued the relevant permits by the Free State.
Steyn, who is a former council member of the South African Predator Association, a trade organisation for the captive breeding industry, gave Meyer unfettered access to his property.
But along with his foreman Johan van Dyke, he now faces animal welfare charges related to the two lions kept in small cages, and may face further charges related to the way lions were being killed and the squalid condition of the abattoir.
What will happen to the 246 lions found at the farm remains unclear. About 100 were reportedly marked for slaughter, but the farm's permits have been revoked. Their fate will not be decided until Steyn and Van Dyke's court case concludes.