HONG KONG (Reuters) - Two global shipping firms that have vowed not to transport shark fin products inadvertently moved a 40-foot container of the controversial delicacy from Nicaragua to Hong Kong this year, both companies told Reuters.

FILE PHOTO: Shark fins, which cost between HK$2,880 ($369) and HK$3,580 ($459) per Chinese catty (1 pound), are on display inside a dried seafood store in Hong Kong January 2, 2013. REUTERS/Bobby Yip/File Photo

The shipment highlights the challenges global industry faces in monitoring the trade that results in the killing of more than 70 million sharks a year, and has pushed more than a quarter of species into extinction according to World Wildlife Fund.

The fins were first loaded onto a vessel called Laura, which is operated by Ocean Network Express (ONE), in Nicaragua in March and then transhipped in Manzanillo, Mexico, onto Mediterranean Shipping Company’s (MSC) vessel Natasha to Hong Kong, according to cargo records seen by Reuters and confirmed by the firms.

The shipment arrived in Hong Kong in April and was first flagged to Reuters by conservation group OceansAsia, which saw bags of shark fin being unloaded on a road in the city’s industrial western district.

Representatives of both ONE and MSC told Reuters the shipment took place but said the contents had not been declared as shark fin.

There was no evidence the shipment broke any local or international laws around shark fin transportation but it did breach both companies’ own policies.

ONE and MSC are among many companies including shipping group A.P. Moller-Maersk APMOLM.UL and Cathay Pacific 0293.HK that banned the carrying of shark fins, in widely publicized campaigns.

A Singapore-based representative for ONE said the cargo was declared as fish products and the company was not aware it was shark fins. ONE was established in 2017 though the integration of the container businesses of Japan's Kawasaki Kishen Kaisa 9101.T, Nippon Yusen KK 9107.T and Mitsui OSK Lines 9104.T.

A spokesman for MSC said the company understood the cargo had been “misdeclared”.

While the sale and consumption of shark fin is legal in Hong Kong and accounts for about half of global trade, products from endangered sharks listed by the U.N. Convention on International Trade in Endangered Species (CITES) are protected and must be accompanied by a permit.

The Hong Kong government has moved to stop illegal trading of sharks fin but false labeling by traders is rampant, allowing shipments to dodge port checks.

Viewed as a status symbol, shark fin is typically eaten shredded in a jelly-like soup that is believed to have nourishing benefits.