London: A Japanese city has warned its residents to be vigilant after lethal blowfish were accidentally sold at a supermarket.

The store in Gamagori sold five portions of blowfish which had not had their toxic livers removed, the warning said. The blowfish, or fugu, is a delicacy, but before it is eaten, the livers must be removed because they contain a deadly poison that is 1200 times more lethal than cyanide. It can kill within minutes of consumption.

A fugu, or a blowfish, is shown at a restaurant in Shimonoseki, southwest of Tokyo. Credit:ITSUO INOUYE

The threat is so real that chefs in Japan must undertake three years of specialist training to obtain a licence to prepare the fish, which holds tetrodotoxin in its liver, ovaries and skin. Three of the five portions were located, and no one has yet been harmed, but two are still missing.

Local officials have warned the population not to eat blowfish until the missing portions are recovered.