3 August 2010 Last updated at 05:35
Demand for shark fin soup in Asia has been blamed for the illegal killing of nearly 300,000 sharks off Brazil, an environmental group has alleged.
The Environmental Justice Institute in Brazil has accused a seafood exporter (Siglo do Brasil Comercio) of illegally killing nearly 300,000 sharks.
It is suing for what it says is massive damage to the marine ecosystem.
It alleges that many of the sharks were thrown back into the sea after their fins were taken for clandestine export.
The environmental group is suing the company for $790m (£500m) in damages for its alleged sale of 290,000 sharks since 2009.
"As we can't put a value on life, we have calculated the impact on the ecosystem," said the director of the group, Cristiano Pacheco.
"We think the sharkfins were exported clandestinely, in containers, likely from the ports of Rio Grande do Sul to the Asian market," Mr Pacheco said.
It is illegal to separate shark fins from the carcasses in Brazil, but the high value placed by Asian diners on the fins has encouraged the practice of taking the fins only and throwing badly damaged sharks back into the sea.
Demand for shark fin delicacies in China has also been explained by some analysts as a product of the growing size of China's middle class, where ostentatious shows of consumption and wealth are fashionable.
"This is an extremely serious situation and represents only a fraction of the sharks that are illegally killed off Brazil's northeast coast," Mr Pacheco said.
"The massive and illegal fishing is doing irreversible harm to the ocean's ecosystem, because sharks are at the top of the food chain."
The Associated Press reported that calls to the company office in Brazil went unanswered.
The enforcement agency of Brazil's environment ministry said that it raided the company premises in May. It said it found only separated fins and that the company had no documentation to explain their origin.