NEW YORK • The eatery has netted three Michelin stars, but the authorities are not impressed with the quality of its fish.

Masa, one of New York's most expensive restaurants, received a warning letter from the Food And Drug Administration (FDA) dated Oct 16 - alleging violations of federal rules that govern seafood imports. "Your fresh trevally and fresh Katsuwonus pelamis (Katsuo), also known as skipjack tuna or bonito, have been prepared, packed or held under insanitary conditions whereby they may have been rendered injurious to health," the agency wrote.

Ms Tina Clabbers, a representative for Masa, which earned three Michelin stars for its US$595 (S$809) tasting menu, said the eatery takes the "FDA regulations very seriously and, of course, food safety is always a priority".

"We are working closely with our purveyors in Japan to get this resolved quickly," she added.

While the FDA does not typically regulate individual restaurants, the agency has jurisdiction over seafood importers.

Inspectors visited Masa on June 22, according to the letter, which did not reveal the name of the restaurant's fish supplier. The letter does not specify the precise nature of the violation.

The regulation for which Masa was cited requires fish importers to ensure foreign suppliers meet the same standards for safety that domestic processors must adhere to.

The FDA letter said Masa "must implement an affirmative step" to comply with the seafood import rules, but failed to do so for the fresh trevally and Katsuo.

New York City health inspectors gave the restaurant an A grade in July last year.

BLOOMBERG