The poisoning incident of Chinese dumplings exported to Japan was a special case of sabotage and it is unlikely to have happened in China, said China's security and quality watchdogs on Thursday.

"After comprehensive investigation, we believe there's little chance that methamidophos was put into dumplings in China," said Yu Xinmin, the Ministry of Public Security (MPS) criminal investigation bureau deputy director, at a press conference.

The General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), China's quality watchdog, told the media it came to the same conclusion after finding no harmful chemicals in relative products and samples and no abnormal operations on the part of the Chinese producer.

"We conclude that the dumpling poisoning incident is an individual contrived case instead of a case of food safety resulting from pesticide residue," said Wei Chuanzhong, AQSIQ deputy chief.

In January, Japanese media reported 10 people fell ill in the country after consuming frozen meat dumplings that were found to contain methamidohpos. They were produced by Tianyang Food Plant based in north China's Hebei Province.

Experiments show methamidohpos can penetrate into sealed packages from the outside, said Wang Guiqiang, an expert of evidence authentication with the ministry.

The Japanese police argued it's unlikely the sabotage happened in Japan. They said they concluded the opposite results of similar experiments and found impurities in the methamidohpos, which showed the substance was not produced in Japan.

"Our tests can better reflect the real situation as our choice of materials and design are closer to realities," Wang said.

He noted impurities found by the Japanese police were usual byproducts in methamidophos and couldn't prove the source of the substance.

The conclusions of Chinese and Japanese police were different but both based on their own evidence, said Yu, urging the two countries to further cooperate in investigations until the truth comes out.

"I didn't mean the crime must have been committed in Japan," he told reporters.

Meanwhile, Wei said the ongoing investigation can't eliminate the possibility of the pesticide being obtained from other countries and then brought to Japan. He stressed investigators should be open to all possibilities.

Chinese police caught an unidentified number of Japanese journalists trying to carry methamidophos they illegally purchased in Hebei out of the province on Feb. 15, Wei said. He didn't specify their identity or other details.

China banned the use of methamidophos in agricultural production in 2007 and has made it illegal to produce, sell, carry and transport the substance since the beginning of 2008.

(Xinhua News Agency February 28, 2008)