Robert De Niro's restaurant chain sells endangered tuna

A Michelin-starred restaurant chain part-owned by the actor Robert De Niro is serving endangered bluefin tuna at its London outlets without telling customers, DNA tests have shown.

Undercover investigators targeted the Nobu chain, which has 21 restaurants on four continents and is the haunt of celebrities such as Madonna, Kate Winslet and Leonardo DiCaprio.

At three Nobu restaurants in London, investigators from the environmental group Greenpeace ordered tuna dishes described on the menu only by Japanese terms for the cut of the fish they were from.

They asked staff to identify the tuna species used. Samples were later tested to determine the type. Dishes from all three were Atlantic bluefin.

The distinction is important because the Atlantic bluefin and the southern bluefin are listed as critically endangered by the International Union for the Conservation of Nature's Red List because of overfishing. Most sushi eaten in Britain is from less endangered species such as yellowfin, but Japanese chefs are known to consider bluefin the most delicious.