Police filed charges of attempted murder Friday against a Chinese man involved in the poisoning of frozen "gyoza" (dumplings) exported to Japan seven years ago.
Lu Yueting, 40, is already in prison in China, having been sentenced to life imprisonment last January for poisoning frozen dumplings that caused four people in China to fall ill and 10 to get sick in Chiba and Hyogo prefectures.
With the largely symbolic action, Chiba and Hyogo prefectural police terminated their investigations into the incident, which triggered concerns over the safety of food imports from China. The prosecutors are expected to drop the case.
Lu was charged with injecting methamidophos insecticide into frozen dumplings at a Tianyang Food factory in Hebei Province in October 2007 when he was a temporary employee there. The dumplings were exported to Japan where they caused illnesses in December 2007 and January 2008.
The man admitted to the charge during interrogations in China, explaining he wanted the factory's manager to improve wages and welfare for workers, the Japanese police said.