Environmental activists claim to have to discovered the world's largest shark slaughterhouse, providing meat from the endangered animals for soup, health supplements and beauty products.
Hong Kong's WildLifeRisk infiltrated the factory in the Pu Qi township in Zhejiang Province, China, which they claim kills more than 600 endangered whale sharks a year, as part of a four-year-long investigation.
They also discovered two other threatened species of shark being slaughtered in the abattoir, with DNA testing of samples confirming traces of basking and great white sharks.
Some of the meat was supplying Chinese restaurants in France and Italy. Shark's liver oil was exported to the United States and Canada as fish oil.
Paul Hilton and Alex Hofford, directors of the group, said in their report that they had been tipped off in 2010.
"How these harmless creatures, these gentle giants of the deep, can be slaughtered on such an industrial scale is beyond belief," they said in a statement.
"We went there three times in the past three years and each time the scale of the slaughter was truly staggering.
"It's even more incredible that this carnage is all for the sake of non-essential lifestyle props, such as lipsticks, face creams, health supplements and shark's fin soup."
The report said the activists went undercover, posing as a seafood trading company. They were told by the general manager, captured on video, that more than 600 whale sharks were processed there each year.
The report said sharks were caught in the South China Sea and the Pacific Ocean and around the waters of the Philippines, Indonesia and Mexico.
It is legal to have a shark-processing plant, but certain species are protected both internationally, and by China.
Whale sharks are protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora, to which China is a signatory.
“If we hope to save species such as the whale shark from extinction, we must hold individuals accountable for their violation of international protection laws and demand transparency so that consumers can make informed decisions about the products they buy,” the conservationists said.
Environmental groups in China have expressed their horror. May Mei, WildAid China’s chief representative said that many people in China had now given up eating shark.
“It is shocking to see the slaughter of whale sharks on this scale. This would shock most people in China as well," she said.
Mei said a WildAid survey in 2013 showed that 85% of Beijing, Shanghai, Guangzhou, and Chengdu residents surveyed had given up eating shark fin in the last three years.
"Consumption still persists, however, so we are continuing our campaigns to ‘say no to shark fin’. As this news shows us, we need to improve awareness not only at the consumer end, but also in coastal areas and fishing ports that process marine products, especially on the protection status of endangered species. We hope the government will take action to close factories such as this one that are illegally processing nationally protected species.”