Chinese authorities have told Japan it is highly likely that frozen dumplings linked to food poisonings in China in June were contaminated by workers at the Chinese factory where they were made, sources close to Japan-China relations said Sunday.
Tokyo and Beijing have been at odds over where the "gyoza" dumplings were contaminated with a toxic substance, with both denying tampering in their countries.
China's effective acknowledgment came after authorities there interrogated 55 employees of Tianyang Food in Hebei Province, suspecting one or more may also have been responsible for separate food poisoning incidents that occurred in Japan, the sources said.
The Chinese investigators suspect factory insiders may have contaminated Japan-bound dumplings with pesticide because of a grievance possibly related to Japan, working conditions or interpersonal relations, the sources said.
The Foreign Ministry said Thursday the Chinese Ministry of Public Safety notified Japan that the dumplings involved in the June food poisonings in China had not been put on the legal market.
According to the sources, when the Chinese authorities made the notification, they also indicated that Tianyang Food workers were suspected of tampering with the dumplings and selling them illegally after the products were recalled.
Methamidophos was reportedly found in the dumplings. That is the same pesticide detected in the food poisoning cases in Japan, which sickened 10 people last winter.
The Chinese authorities have also informed Tokyo they are conducting a comparative analysis of the toxic substance found there and in Japan.