The findings, released last week in an international scientific journal, said the strain called H5N1 Fujian-like was found in almost all poultry outbreaks and some human cases in southern China, and was now also the dominant version in Hong Kong, Laos, Malaysia and Thailand.
"There is no such new Fujian-like virus variant at all. It is utterly groundless to assert the outbreak of bird flu in Southeast Asian countries was caused by AI (avian influenza) and that there would be a new outbreak wave in the world," Jia Youling, director of the Chinese Agriculture Ministry's veterinary bureau, said in a statement.
"The data cited in the article were unauthentic and the research methodology was not based on science, therefore their arguments were not tenable and totally against the facts," Jia said.
The study Jia criticized was released in the Proceedings of the National Academy of Sciences, and was conducted by scientists in Hong Kong and the United States.
It charted the spread of the Fujian-like strain by testing geese and ducks found in live markets in six southern Chinese provinces beginning in June 2005.
Over the course of the year, the strain became more pervasive, the study said. Among the 108 samples taken from Chinese poultry in April and June 2006, 103 or 95 percent were infected with the Fujian-like strain, it said.
The researchers said it was unclear how the strain had emerged or spread so widely, reports AP.
International health experts have repeatedly complained about Chinese foot-dragging in cooperating on investigating emerging diseases such as bird flu and SARS, which emerged in China's south in late 2002 and eventually killed 774 people worldwide.
Last week, the World Health Organization criticized the Agriculture Ministry for not sharing bird flu samples with the international health body since 2004. Sharing is key in helping health experts track the diseases and ultimately develop vaccines.