South Korean prosecutors have requested a one-year prison sentence for the owner of a Michelin-starred restaurant accused of using ants as a dessert garnish, local media reported.

Ants are not among the 10 species of insects approved for human consumption under the country’s laws. The approved list includes grasshoppers, locusts and two-spotted crickets, among others.

Prosecutors also asked on Monday that the restaurant, which has two Michelin stars, be fined 20 million Korean won ($13,510; £10,100).

The owner admitted to serving ants, but argued that they were used in a “small part” of the restaurant’s 15-course menu, as a topping for sorbet, and that diners were told they could opt for non-ant toppings.

The case came to light after officials from the Ministry of Food and Drug Safety found reviews that diners had posted online with photos of dishes dotted with ants.

Researchers estimate that about 49,000 ants, imported from the United States and Thailand, were used in various dishes over four years.

Health authorities also found that the restaurant used ants that “contained up to 55 times more heavy metals than typical edible insects,” according to a report by The Chosun Daily.

South Korean authorities consider several criteria to decide whether insects can be approved as food. These include food safety risks, toxicity, nutritional value and whether they can be grown and processed hygienically.

In his defense, the restaurant owner argued that only 60% of the diners had chosen to try the ants, while the rest were served alternatives such as fermented vinegar and edible flowers.

He added that restaurants in other countries, such as Australia, Denmark and the United Kingdom, also use ants as ingredients.

Court documents did not name the restaurant or its owner. Ten restaurants in South Korea, all located in the capital Seoul, have received two Michelin stars.

The Michelin Guide awards up to three stars to restaurants based on quality of ingredients, mastery of flavor, cooking technique, chef personality and consistency.

Two stars designate restaurants that make “excellent cuisine” and that are “worth visiting,” according to Michelin criteria.

The court will issue its verdict on September 2.

Ants are eaten, sometimes even valued as a delicacy, in various Asian, African, and Latin American cultures. Weaver ants and their eggs are used in Thai and Cambodian cuisine, while in Colombia queen ants are as prized as caviar.