A senior Chinese quality control official said Wednesday there was no possibility of deliberate contamination of dumplings on the China side as the plant were strictly managed.
China would continue to step up checkups in the production, packaging, and transport of food products made by Tianyang Food Plant, said Wei Chuanzhong, deputy chief of the General Administration of Quality Supervision, Inspection, and Quarantine (AQSIQ).
Japanese police have so far confirmed at least 10 people fell sick after eating dumplings laced with the highly toxic organophosphate pesticide called methamidophos made by Tianyang Food in northern China's Hebei Province.
Investigations by Japanese police indicated the poisoning case was more likely a deliberate one, rather than a food safety scare, Wei said.
China was ready for sincere cooperation and joint investigation with Japan to seek the truth behind the poisoning case, amid efforts to safeguard Japanese people's safety and bilateral strategic relations, he noted.
"China is willing to work with Japan to set up a long-term food safety mechanism between the two neighbors. We hope investigators could soon find the truth and publicize it to reduce the damage to the bilateral relations," he said after meeting a four-member Japanese investigation team in Beijing.
Wei said he hoped the Japanese instigators would tell exactly what they saw in China after going back to guide more impartial and rational media report, instead of reporting exaggeration on groundless speculation.
A joint investigation team of China and Japan said early Wednesday morning they had not detected abnormality in the Tianyang Food after a half-day investigation tour to the company.
"The plant is very clean and well managed, and no abnormality has been detected," Harashima Taiji, head of the Japanese investigation team, told the press. Japan would conduct further analysis based on information and data collected in the plant, he said.
Taiji added the Japanese side hoped to get more support in later investigation after touring the plant and getting all the materials it wished to check.
Japanese media reported nearly 300 people have sought medical treatment, with one girl in serious condition, since a Japanese company said last week frozen meat dumplings produced at the Tianyang Food contained insecticide.
Japanese authorities found an insecticide called methamidophos in the vomit of the poisoned people and food packages at their houses.
But tests showed that the rest of the dumplings from the same batches sold in Japan, totaling more than 2,000 packages, were safe. So were all the other products made by the Chinese company, Wang Daning, director of AQSIQ's department of food import and export safety, said earlier.
Earlier report said while suspicious clues such as small holes on some packages remain inexplicable, it's currently still unknown whether the food products were contaminated during the production and transportation process in China.