South Koreans who enjoy a rare flavour of soju, the country's most beloved alcohol, have been discouraged from mixing wasps into their drinks as a tonic after a health warning from the food ministry.

The Ministry of Food and Drug Safety said mixing wasps and soju could pose health risks for tipplers after the drink gained popularity on the internet.

Some drinkers believe wasp soju is especially good for high blood pressure and diabetes. Some also add other insects, including centipedes and earthworms, to concoct their own soju health tonics.

South Koreans often mix soju with other ingredients. "Somac", a mixture of soju and beer, is the most popular soju-based cocktail.

"It is no more than a rumour going around ordinary people that wasps could help restore health," Kim Seung-hwan, a researcher at the Food and Drug Safety Ministry, told Reuters.

Kim said it was a sub-culture that had been around for a long time, but it had worsened since some people began sharing the recipe and even selling it online.

"That's when we felt a need to warn people of the danger before it gets out of control," Kim said.

Authorities discourage people from using wasps in food because they can cause severe allergic reactions that could lead to choking.

An illegal wasp-based soju shop in Hwaseong, a city south of Seoul, was uncovered in February, according to a statement released by South Korea's special judicial police.

The ministry said it was not aware of the exact number of people who were involved in making soju with wasps but stressed that everyone should be aware of what they should and shouldn't eat.

"Isn't it too obvious that wasps and centipedes aren't edible?" Kim said.