On Thursday, environmental advocates accused a startup from Mexico of breaking international trade regulations by selling a dietary supplement made from endangered totoaba fish to multiple countries, including the United States and China.

According to advocates, there are concerns about The Blue Formula potentially selling illegally caught fish from the wild.

The company’s product, touted as “nature’s hidden gem,” is a compact packet of powder infused with fish collagen that can be added to any beverage.

According to the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which both Mexico and the U.S. have signed, it is illegal to export totoaba fish for sale unless they have been bred in captivity with a specific permit. Additionally, under U.S. trade law, it is also illegal to commercially import this protected species.

Cetacean Action Treasury, an environmental watchdog organization, first mentioned the company in November. On Thursday, a coalition of environmental charities including The Center for Biological Diversity, National Resources Defense Council, and Animal Welfare Institute filed a formal complaint to CITES.

The Blue Equation did not promptly reply to an AP inquiry for a statement.

The company’s website states that it is committed to sustainable practices by obtaining fish from Cygnus Ocean, a certified farm that breeds totoaba, and allocating a portion of their earnings towards releasing farmed fish back into their natural habitat.

According to environmental organizations, Cygnus Ocean does not possess authorization to commercially export their cultivated fish. The farm has also failed to promptly reply to a request for comment from AP.

Although breeding totoaba in captivity has a significantly lower ecological impact compared to wild fishing, advocates such as Alejandro Olivera, the Mexico representative for the Center for Biological Diversity, are concerned that the company and farm could be used as a cover-up.

Olivera stated that there is inadequate monitoring of totoaba traceability in Mexico, making it vulnerable to being used for illegal purposes such as laundering wild totoaba.

Using gillnets to catch wild totoaba is against the law and a main cause of the declining population of critically endangered vaquita porpoises. Recent surveys indicate that there may be less than ten vaquita porpoises left in their natural habitat.

Gillnetting is driven by the exorbitant price for totoaba bladders in China, where they are sold as a delicacy for as much as gold. The Blue Formula’s supplement costs just under $100 for 200 grams.

In October, U.S. Customs and Border Protection discovered totoaba bladders worth over $1 million in Arizona, concealed within a shipment of frozen fish. A similar amount was also seized in Hong Kong during the same month, while en route from Mexico to Thailand.