Federal prosecutors in the US have charged the owner of a California restaurant over alleged sales of whale meat, which was labelled sushi.

The owner was summonsed after marine activists accused him of serving them the illegal whale meat.

The owner of the Hump restaurant in Santa Monica, Kiyoshiro Yamamoto, 45, was charged with illegally selling an endangered species.

If he is found guilty of the offence, he could be fined $100,000 and spend a year in prison. The company itself could be fined $200,000.

The whale was allegedly served to customers under the chef's choice menu item, in which the dish was described as a $600 delicacy.

Two diners who requested the dish were working undercover for the producers of the Oscar-winning documentary, "The Cove," who were themselves secretly recording the incident.