The Chinese Ministry of Health on Monday confirmed a man had died from the H5N1 bird flu virus in Xinjiang Uygur Autonomous Region.

The victim, a 62-year-old farmer, became ill on June 19, and died on July 12.

Epidemiological research showed the man did not have close contact with any human cases of bird flu and sick or dead poultry in the last month of his life.

The regional center for disease control (CDC) and prevention tested his samples and got negative results 14 days after he fell ill, but the re-test by the national CDC on July 16 indicated he was H5N1 positive.

On August 2, the national CDC tested the rest of his samples left from previous tests and again got positive results, said the ministry.

The ministry confirmed it as a human case of bird flu by both Chinese and WHO standards and reported the new case to the World Health Organization.

Local health authorities have tightened prevention and control measures and have found no abnormal symptoms of the people who had close contact with the farmer.

This case brings China's total human cases of bird flu to 21 and the death toll from the disease to 14.

An outbreak of bird flu in poultry in Xinjiang's Aksu City was confirmed on July 14.

A total of 3,045 chickens were killed by the disease and another 356,976 were culled when the outbreak was confirmed, according to the Ministry of Agriculture.

It announced on August 10 that the outbreak had been brought under control.

The information office of the Ministry of Health said they could not link the new human case with outbreaks among poultry in the region.

The source of infection for the new case is still unclear, spokesman of the Ministry of Health Mao Qun'an told Xinhua. The direct causes of most of the previous cases in China are also unknown.

Last week, the Ministry of Health confirmed the mainland's first human casualty of bird flu actually occurred in November 2003, two years before the previous official figures.

The case, in which a 24-year-old man died in Beijing, was first revealed by eight Chinese scientists in June who published a letter in the New England Journal of Medicine. The ministry then carried out parallel tests with the WHO to confirm their claims.

The WHO has said it was the first ever human infection from the H5N1 outbreak.

By August 9, the WHO had recorded 236 human cases of bird flu, including 138 fatalities.