China has promised severe punishment for officials caught concealing deaths from H1N1 swine flu after a medical expert said suspect cases may have been held back by local governments.

The Health Ministry said China had adopted a new H1N1 accounting method earlier this month. If a person was confirmed with H1N1 and then died, the case should be reported as death from H1N1, whether or not there was another condition.

People responsible will be punished if reports of H1N1 virus cases are held back, lied about or delayed, said Deng Haihua, spokesman for China's Health Ministry, according to a notice on the ministry's website ( seen on Friday.

Zhong Nanshan, respected by many in China for his candor and work fighting Severe Acute Respiratory Syndrome (SARS) in 2003, said he did not believe the national H1N1 death toll of 53, the Southern Metropolis Daily reported on Thursday.

Zhong, who heads the Guangzhou Institute of Respiratory Diseases in southern China, said that some areas have not been testing deaths from severe (pneumonia) and treating them as cases of ordinary pneumonia without any question.

The World Health Organization does not have a standard for which deaths to attribute to H1N1, although it does define how to diagnose cases, spokeswoman Vivian Tan said from Beijing.

We don't think anything unusual is happening here, in terms of how the virus is spreading or how virulent it is, Tan said.

The H1N1 flu strain affects the respiratory tract. Patients who become severely ill or die typically suffer from pneumonia, either brought on directly by the virus or due to secondary bacterial infections.

The World Health Organization reported more than 503,536 laboratory confirmed cases of H1N1 worldwide on November 8, with at least 6,260 deaths. However, it has stressed for months now that the figures were only the tip of the iceberg.

It urged countries to place more resources on mitigating the disease rather then on costly prevention measures or testing everyone. All WHO and the U.S. Centers for Disease Control and Prevention will say is that millions have been infected.

China's previous method attributed the death to previously existing conditions but not to H1N1, thereby reducing the number of cases reported as H1N1 death cases, a separate notice on the Health Ministry's website said.

A ministry official told Reuters it would no longer issue cumulative tolls, only new cases and deaths.

That will make it difficult to determine the actual extent of H1N1 deaths in China, which based on previous figures have been statistically much lower than in other countries.