The "dumpling poisoning" case involving China and Japan was believed by both sides to be an individual contrived case of sabotage, and should not have any impact on Chinese President Hu Jintao's planned state visit to Japan, China's top quality control official said on Thursday.

"Chinese and Japanese police share the view that the dumpling incident is an individual contrived case of sabotage. I believe it won't have any impact on President Hu's planned state visit to Japan," Li Changjiang, head of the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), told a press conference on the sidelines of the annual parliament session.

Li said that investigation into the case is still underway, while closer cooperation between the police of China and Japan is needed to find out the truth.

Japanese media reported that 10 people fell ill in December and January after consuming frozen meat dumplings produced by a Chinese food company. The Japanese authorities concerned found the insecticide methamidophos in the vomit of those poisoned and in food packages at their houses.