China is investigating a food poisoning incident in Japan concerning frozen Chinese dumplings imports, promising a timely release of the investigation results, said the country's quality watchdog on Thursday.

At least 10 people in Japan's Hyogo and Chiba prefectures reported stomach ache, vomiting or diarrhoea after eating the dumplings, according to Japanese media.

China was "highly concerned" with the issue and had immediately contacted the relevant departments in Japan after being advised of the problem on Wednesday afternoon, said the General Administration of Quality Supervision, Inspection and Quarantine.

Japanese distributor JT Food Company announced a recall of the dumplings that were alleged to be tainted by phosphorus, a chemical substance.

Products manufactured by the Chinese food company Tian Yang, situated in Hebei Province, have also been withdrawn.

(Xinhua News Agency January 31, 2008)