The actor Robert De Niro has come under fire from environmental activists after being found to be serving up endangered fish at Nobu - his chain of Michelin starred restaurants in London.
The environmental group Greenpeace went undercover and ordered tuna dishes from three different branches of the restaurant.
Staff were unable to identify the tuna species used but later tests revealed all three samples to be Atlantic bluefin tuna.
The Atlantic bluefin together with the Southern bluefin are both so at risk that they are listed as Critically Endangered by the IUCN (International Union for the Conservation of Nature), and the World Wildlife Fund has called for a complete ban on selling the species.
Nobu does not name the species of tuna used on any of its menus and although it is not illegal to sell bluefin tuna, many chefs have dropped it from their menus believing it is irresponsible to stock a fish so at risk from further overfishing.
The Atlantic (or Northern) bluefin tuna can grow up to three metres in length, 680kg in weight and can fetch prices of up to $180,000 dollars.
Willie Mackenzie of Greenpeace is quoted in the Telegraph saying: "Nobu and Robert De Niro are clearly making a great deal of money serving up endangered fish and they were reported this year as trying to sell a controlling share of their restaurant chain at a valuation of $400 million.
Now it turns out that Nobu's celebrity clientele are unwittingly pushing bluefin tuna towards extinction, and they should demand that the restaurant stop serving it up immediately.
"If you were served up something labelled as 'steak' in a restaurant, and only found out later that you had eaten tiger or rhinoceros meat, you would be outraged."
Mr De Niro and Nobu declined to comment to The Telegraph.