BEIJING - China has ordered more accurate reporting of A(H1N1) flu deaths after a doctor renowned for helping expose the scale of the 2003 SARS outbreak claimed the true number of fatalities was being covered up.

The health ministry "reaffirms that health authorities at all levels must conscientiously perform A(H1N1) prevention and control reporting work," according to a statement posted on its website late Thursday.

Zhong Nanshan, a medical expert in southern China's Guangdong province, was quoted by a newspaper there on Thursday as questioning the official nationwide tally.

Zhong attracted attention for his willingness to communicate the uncomfortable truth about Severe Acute Respiratory Syndrome, defying official propaganda that initially aimed to cover up the extent of the outbreak.

Zhong said he believed many dead patients were left undiagnosed in order to conceal the true number of swine flu deaths, which the government has put officially at 53, out of nearly 70,000 cases.

The ministry statement, quoting spokesman Deng Haihua, said it was "strictly prohibited to conceal, omit, or delay reports of A(H1N1) deaths," adding that those who did so would "be held accountable".

However, it did not deny outright that some cases might have been concealed.

Chinese officials initially tried to cover up the SARS outbreak to prevent a politically embarrassing health threat from being exposed, only coming clean after it began to spill into neighbouring countries.