The market sold five packages of fish without removing their livers, which can contain a potent neurotoxin.
A Japanese city has warned residents to avoid eating a potentially deadly blowfish that was inadvertently sold to shoppers at a local supermarket.
Pufferfish, or fugu, is an expensive delicacy often served in the form of paper-thin sashimi slices.
That warning had been partially successful, Takayanagi said: "Three packages will be retrieved today, but we still don't know where the remaining two are".
Since 2000, there have been 26 deaths from incorrectly prepared puffers, majority at home rather than in restaurants.
The inclusion of the liver in the package could have contaminated the other meat with the fugu poison.
The two people who consumed the fish have not reported any health problems as this time.
Dozens of people are poisoned by fugu every year.
The illegal sales surfaced yesterday when a buyer of one package took it to a health centre.
Fugu is widely eaten in Japan but can be served in restaurants only after a qualified chef has removed the liver and ovaries or testes, which harbour tetrodotoxin, which affects the nervous system. "With four other packages sold but unaccounted for, city officials alerted residents via the emergency loudspeakers normally used for earthquakes and other disasters".
"Health authorities found that the store had been selling the liver of the particular kind of blowfish, called 'yorito fugu, ' or blunthead puffer, for years because it's almost non-toxic, health ministry official Yohei Ohashi said".
Japanese fugu fish is deadly to humans if incorrectly prepared.
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.