A sushi chef was sentenced to a $5,000 fine and 200 hours of community service at a U.S. federal district court for serving whale meat to customers at a high-end sushi restaurant in California in 2009 and 2010, an act banned under U.S. law.

As the head chef of The Hump, a now-defunct sushi restaurant in Santa Monica, Kiyoshiro Yamamoto, a naturalized U.S. citizen, served and sold sei whale meat in violation of the Marine Mammal Protection Act, according to Monday's ruling.

The sei whale is designated by the U.S. government as an endangered species.

Yamamoto was also sentenced to two years of probation.

"I will reflect on my action. I'm sorry," he told the judge in Japanese.

The case came to light after staff members who worked on the U.S. film "The Cove," an Oscar-winning documentary about a controversial dolphin hunt at the seaside town of Taiji, Wakayama Prefecture, tipped off local authorities after secretly filming the meat they ordered and pocketing samples, according to local media.

Earlier this month, Susumu Ueda, another chef who worked at the restaurant, was given the same sentence in connection with the case.