(CNN) - A Japanese city issued an emergency alert to residents Monday after two people ate potentially dangerous portions of fugu fish that should not have been sold.
Five packs of Yorito fugu (blunt head blowfish) were sold at a supermarket located in Gamagori city, in the central Aichi Prefecture, by a licensed employee who had not removed the livers, according to Hiroko Mizuno, an official from the district's Life and Hygiene department.
The fish, also referred to as puffer fish, contains a toxin hundreds of times more poisonous than cyanide; its liver alone can contain enough poison to kill five men. Japan has laws in place to ensure it is prepared and detoxified properly before it is sold.
Fugu, with its lethal innards, is considered a winter time delicacy in Japan, with high-end Tokyo restaurants charging customers 22,000 yuens ($198 US) to risk death.
The two people who consumed the fish have not reported any health problems as this time. However, Gamagori city activated an emergency warning to its citizens alerting them through all wireless systems, including community loud speakers, against eating the fugu and recalling the product.
Mizuno told CNN that this particular type of blowfish usually has very weak or no poison, but the food hygiene laws prohibit the sale of any liver given its potentially poisonous implications. The liver should never be eaten because only testing can detect the poison.
Two packs of the recalled fish were located and returned on Monday night after the city's quarantine office was alerted by a consumer who had bought the product and found the liver still inside. The office has since launched an investigation into the supermarket, Mizuno said.
A third pack was later returned, accounting for all five packages.
Mizuno added that the supermarket told the quarantine office that their licensed employee who cut the blowfish thought this type of fugu was not poisonous as they had previously sold it with its liver before.
Fugu's popularity in Japan
Fugu meat is sold regularly for sashimi and hot pot ingredients.
Toshiharu Hata, a fugu wholesaler in Japan previously told CNN it is traditionally served as transparent paper-thin strips on porcelain pates.
"Master chefs cut them into the shapes of chrysanthemum petals, Mount Fuji or into animals like peacocks, turtles and butterflies. Every plate is a work of art, every dish is a work of science," Hata said.
According to Western Australia's Department of Fisheries, puffer fish are the second most poisonous vertebrate in the world after the golden poison frog.
To prepare such a high-risk food, chefs must undergo a three-year apprenticeship before being allowed to take the examination, in theory ensuring precise execution and making it safe to eat.
According to the Japanese health ministry, incorrectly prepared fugu has been found to be one of the most frequent causes of food poisoning in the country.
Following Monday's incident, the supermarket will no longer sell blowfish.
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