Los Angeles, California (CNN) -- Federal authorities have charged a trendy Santa Monica sushi restaurant with serving whale meat -- an investigation that was spurred by the team behind the Oscar-winning documentary, "The Cove."

Prosecutors charged Typhoon Restaurant Inc., the parent company of The Hump, and one of its chefs -- Kiyoshiro Yamamoto, 45 -- with the illegal sale of a marine mammal product for an unauthorized purpose.

While it is considered a delicacy in Japan and some other countries, meat from whale -- an endangered species -- cannot be sold legally in the United States.

The misdemeanor charge carries a federal prison sentence of up to a year and a fine of up to $200,000 for the company, said Thom Mrozek, spokesman for the U.S. Attorney's Office.

Lawyers for Typhoon could not be reached for comment. But the restaurant told the Los Angeles Times it accepts responsibility and will pay a fine.

The investigation began in October when two members of the team that made "The Cove" visited The Hump, officials said.

"The Cove," which exposes the annual killing of dolphins at a Japanese fishing village, won the Academy Award for Best Documentary on Sunday.

The restaurant, located at the Santa Monica Airport, is known for its exotic fare. Its Web site asks diners to surrender themselves to its chefs for "a culinary adventure ... unlike any that you have previously experienced."

Armed with a hidden camera, the two women captured the waitress serving them whale and horse meat and identifying them as such, a federal criminal complaint said. A receipt from the restaurant at the end of the meal identified their selection as "whale" and "horse" with the cost -- $85 -- written next to them.

The women snuck pieces of the meat into a napkin and later sent them for examination to a researcher at Oregon State University. He identified the whale sample to be that of sei whale, prosecutors said.

The sei is found throughout the world's oceans.

Whalers began to hunt them after the population of blue and in whales declined due to overfishing. It is now considered an endangered species.

In February and March, the activists returned and again asked for -- and were served -- whale meat, the criminal complaint said.

A DNA test of the meat smuggled out after the February visit confirmed it to be meat from the sei whale, Mrozek said.

During the last visit in March, officials with the U.S. Customs and Border Protection, the U.S. Fish and Wildlife Services and the National Oceanic and Atmospheric Administration observed the activists asking for "kujira" or whale meat.

One of the officers then saw the sushi chef leave the restaurant and return with a wrapped package that he seemed to have retrieved from a parked Mercedes, the complaint said.

The chef then told a customer it was whale meat, the document said.

The next, officials raided the restaurant and chef Yamamoto admitted that he had served whale meat, the complaint said.

"Someone should not be able to walk into a restaurant and order a plate of an endangered species," said U.S. Attorney Andre Birotte Jr.

Authorities do not yet know where the meat came from.

Conservation agencies are engaged in an ongoing feud with Japan over whaling.

In the early 1980s, the International Whaling Commission determined that there should be a moratorium on commercial whale hunting.

Whaling is allowed under international law when done for scientific reasons, which Japan cites as the legal basis for its hunts.

The country's annual hunt kills up to 1,000 whales a year.

Many in the international community believe that such hunts amount to needless slaughter.

Critics say that Japan's research is actually a pretext for retrieving whale meat to be sold in markets and restaurants.