The Chinese Government has announced a 17% jump in Aids cases, saying up to 850,000 people were infected with HIV by the end of last year.
The figure is significantly higher than the previous official estimate of 600,000 announced in mid 2001.
A blood-selling scheme in central China infected thousands
The number of people suffering from full-blown Aids could be as many as 200,000 and more than half of those are believed to have died, the official Xinhua news agency quoted China's disease control centre as saying.
Those figures is still way below estimates by experts at the United Nations and the World Health Organisation - who say as many as 1.5 million could be infected.
But correspondents say the announcement is another indication that China is confronting the true extent of its Aids epidemic.
It follows an admission six months ago of a huge Aids crisis in central China's countryside, following years of denials.
Entire villages in Henan province became infected from the mid-1980s and the mid-1990s as a result of a blood-bank scheme, whereby peasants sold their blood for money.
Collectors pooled the blood, extracted the plasma and then simply pumped the mixed blood back into the donors, causing the virus to spread.
And last November China held its first national Aids conference, in what observers said was a sign the country was starting to take the problem seriously.
Yet experts still believe the Chinese Government does not really know how many of its citizens are infected.
It has not conducted comprehensive surveys and many local officials are accused of
suppressing information in a reluctance to
acknowledge prostitution or drug trafficking in their areas.
Needle-sharing among drug users is of particular concern, particularly in Xinjiang and Yunnan provinces, according to a report last year by UNAids and the WHO.
Heterosexually-transmitted epidemics are also on the increase, with HIV rates reaching 10.7% among sex workers in Guangxi province during 2000, up from 6% in 1999.