The Chinese Foreign Ministry said the admission may be key in resolving the dispute between the two countries over whether a pesticide turned up in the dumplings in China or Japan, Kyodo reported.

"There was a dumplings food poisoning case that took place in China in mid-June," the Foreign Ministry's spokesperson's office said in a statement sent to Kyodo News. "The Chinese government places great importance on the incident. The public security authorities are currently investigating with their utmost effort."

The statement came after questions were raised about whether food poisoning occurred in China from frozen dumplings recalled by Tianyang Food in Japan. Sources told Kyodo said Chinese consumers suffered food poisoning in June after eating the dumplings.

Japanese and Chinese authorities investigating the matter are divided about where the pesticide methomidophos first appeared in the dumplings.