Environmental activists have claimed to have uncovered the world's largest whale shark slaughterhouse in south eastern China, killing around 600 of the endangered species a year.
Hong Kong-based conservation group WildLifeRisk said it discovered the factory in the town of Pu Qi in Zhejiang province, following a four-year investigation.
The group also said that basking sharks are killed, as well as great white sharks – which are given the highest protection order under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
China apparently kills hundreds of whale sharks a year to produce shark oil for health supplements. Undercover footage of the slaughterhouse shows workers cutting up the dotted whale shark fins as well as other species.
Alex Hofford and Paul Hilton of WildLifeRisk said: "We went to Pu Qi three times in the last three years, and on each occasion the scale of the slaughter was truly staggering.
"How these harmless creatures, these gentle giants of the deep, can be slaughtered on such an industrial scale is beyond belief. 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 fin soup.
"We are calling on China's regulatory authorities to enforce the international agreements on this illegal activity now, before these animals are brought closer to extinction."
The Pew Environment Group estimates that whale shark tourism, mainly through recreational diving, is worth about $45m (£28m) worldwide.
According to CITES, to which China is a signatory, the international sale of products from an endangered species is illegal and the trade is unsustainable.
"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," WildLifeRisk added.
Whale sharks are also on the International Union for the Conservation of Nature "Red List" of endangered species.
Growing as much as 40ft (12 metres) ,the whale shark is also the largest fish in the world and can weigh around 11 tonnes.