The world's biggest whale shark factory has been found in southern China and processes around 600 sharks in a year. Hong Kong-based conservation group WildLifeRisk called the factory the largest slaughterhouse for one of the world's most endangered species.

The group discovered the whale shark factory in the Pu Qi in Zhejiang province after spending four years in surveillance and investigation. The whale sharks are slaughtered and processed to generate shark oil for use in health supplements. The factory allegedly pays up to $31,000 or 200,000 yuan for every whale shark. As a result, a global network of fishing boats may see this as an chance to make money.

The conservation group's undercover video footage showed Chinese workers cutting dotted and large back fins of whale sharks. Other fins of shark species were also spotted in the facility.

In a statement sent by the group to AFP, it is difficult to believe that the harmless and "gentle giants of the deep" can be slaughtered in an industrial scale. WildLifeRisk stated that they found it "more incredible" to slaughter whale sharks for the sake of heath supplements, beauty products and shark fin soup.

Aside from whale sharks, the group also discovered other shark species being processed including basking sharks and blue sharks. In the undercover video, the owner only known as Li, explained that by killing three species of sharks, the factory can produce approximately 200 tonnes of shark oil every year. Mr Li said he would also resort to smuggling skins of whale sharks out of the country.

A man who was identified as Mr Li's brother said the skins will be exported to European countries like France and Italy where Chinese restaurants use them.

Shark oil exported to North America

WildLifeRisk's Paul Hilton said the shark oil is also exported to the U.S. and Canada in capsule form. Although processing sharks is a legal practice in China, it is particularly illegal for the three shark species seen in the undercover video.

According to Quartz, the North American fish oil industry has flourished in the last 10 years which helped increased prices to $2,100/tonne as of Aug. 2013. Recent statistics indicate that U.S. customers bought about $1.2 billion in fish oil supplements. Research suggests that fish oil provides a range of cardiovascular benefits because of its omega-3 fatty acids.

Whale sharks can grow as much as 12 metres or 39 feet but do not pose a threat to humans since they prey on tiny sea creatures. The shark species is on the "Red List" of endangered species, according to the International Union for the Conservation of Nature. The UN Convention on International Trade in Endangered Species (CITES) obligates countries to prove its exports were taken from a managed population.