TOKYO — Chief Cabinet Secretary Nobutaka Machimura said Friday it is natural to think that a pesticide found inside a sealed Chinese-made frozen meat dumpling package in Japan got in there during the manufacturing process.
''If it is the case that there is a possibility (the pesticide) got mixed into the product before it was sealed, then one would normally think that it happened at the factory (in China where it was made) based on common sense,'' Machimura said at a press conference.
The comment came a day after he warned against making comments on the possible cause of the food-poisoning incidents in Japan involving Chinese-made frozen meat dumplings, in response to remarks made earlier by a Chinese quality control official.
But Machimura said Friday the investigation is still under way to find the cause of the food-poisoning incidents which occurred from late December to January in Japan.
''Investigative authorities are considering various possibilities. For example, that something may have been soaked into the package from the outside,'' the top Japanese government spokesman said.
''I believe careful examinations, including considering whether such a situation is possible or not, are still continuing, and we have not yet reached the stage in which we can determine (the cause),'' he added.
Prime Minister Yasuo Fukuda said in a House of Representatives Budget Committee session in the morning that the investigation ''has gradually come closer to the core,'' although he declined to elaborate.
''We will make efforts to find the cause and make the public feel safe,'' Fukuda said.
Japanese police said Thursday that pesticide was detected on the inner surface of a package of Chinese-made ''gyoza'' dumplings that had not been opened until it was inspected, raising the possibility that the chemical may have been mixed in during or before the packing process in China.
The package, which was one of the 11 packages recalled from an Osaka supermarket, was tainted with the highly toxic organophosphate pesticide called methamidophos, which caused food poisoning in 10 people in three households in Chiba and Hyogo prefectures after consuming similar products.
Fumio Kishida, state minister in charge of quality-of-life policy affairs, said, ''We are paying close attention because we have not seen a case before in which a chemical was detected from inside a sealed product which did not have any holes or damage.'' Kishida emphasized in a separate news conference that the Japanese government is continuing efforts to pursue various possibilities to find out how the dumplings in question got contaminated in coordination with Chinese authorities.
On Friday evening, related Cabinet members met for the third time since the food-poisoning incidents came to light in late January to review recent developments, including the survey missions Japan and China sent to each other's country.
The ministers agreed to work out measures for preventing a recurrence based on two major themes — enhancing the system of consolidating information and reinforcing the system of ensuring safety of imported processed foods, Kishida told reporters after the meeting.
Health, Labor and Welfare Minister Yoichi Masuzoe said separately he asked Foreign Minister Masahiko Komura during the meeting to have a health ministry official in charge of food affairs stationed at the Japanese Embassy in Beijing, and they agreed to work on realizing the idea.
Cabinet members also agreed to consider ways to reinforce Japan's quarantine system to make it more effective in preventing the possibility of tainted products being imported, according to Kishida and Masuzoe.
''The biggest problem is that it looks like we need more time to determine the cause'' of the food poisonings, Masuzoe said. ''As of today, there is nothing we can say in terms of the cause, and this is the biggest stumbling block.''
China's quality control authorities have said no problems were found in the food and production management on the part of the maker, Tianyang Food in China's Hebei Province, and that methamidophos was not used at its factory.
A senior Chinese official said Wednesday that the dumplings could have been deliberately poisoned by people wishing to harm relations between the two countries, and the possibility that a harmful pesticide was mixed in during the dumplings' manufacturing process was ''extremely small.''
Asked to comment on the Chinese official's remarks, Machimura said Thursday he thinks it is ''better not to say something that may seem like specifying a cause at this stage when we are in the middle of investigating.''
In addition to methamidophos, another type of pesticide called dichlorvos was detected in dumplings, also made by Tianyang Food and sold in Japan, a Japanese distributor of the dumplings said earlier this week.