Sam Dolnick, New Delhi: The number of Indians infected with HIV is far fewer than previously believed, according to new figures that appear to vindicate critics who said earlier U.N. assessments of the situation were vastly overestimated.

Experts say the still-unreleased survey results are likely to show that cases of HIV in India, which UNAIDS last year said were the highest in the world at 5.7 million, are in fact well below that mark.

''The actual number we've come up with in aggregate is likely to be lower, and perhaps substantially lower,'' said Ashok Alexander, director of Avahan, the Indian program of the Bill & Melinda Gates Foundation, which helped fund the study.

Alexander declined Friday to offer estimates of what the new total would be, saying the numbers are still being analyzed, and precise figures will not be released for a few more weeks.

The new estimate comes from combining data collected from prenatal clinics, a survey of high-risk groups such as sex workers, and from the government's National Family Health Survey a method Alexander said was more reliable than previous estimates, which relied largely on data from prenatal clinics.

The health survey, the third since 1992-93 but the first to provide an HIV estimate is considered the most comprehensive source and carries the most weight in determining the new figures. It covers about 200,000 people ages 15 to 54, more than half of them women, and was conducted through face-to-face interviews across India between December 2005 and August 2006. It has no significant margin of error.

A statement released Friday by the government's HIV control program, UNAIDS and the World Health Organization acknowledged that the new data provided ''a more accurate picture of the epidemic.'' But it made no mention of the lower estimate an indication perhaps of how sensitive the figures are in India, where billions of dollars (euros) have been poured into prevention programs.

Instead, it pointed out that HIV rates remain high among groups most at risk: sex workers, men who have sex with men, truckers, and intravenous drug users.

Daniel Halperin, an HIV and AIDS expert at the Harvard School of Public Health, said the new data put health officials in a bind.

''On the one hand there's a real HIV epidemic in India and it needs to be addressed, but on the other, there's an understandable concern that people were worried that funding or attention could be diminished if the prevalence numbers come out lower,'' he said.

Health experts in India also stressed that while the new data was good news, HIV is still a major problem, particularly in southern Indian states where rates might be as high as 1 per cent of the general population.

''This is a bit like declaring victory before even fully fighting the battle,'' Alexander said.

This is not the first time India's HIV numbers have been questioned.

Halperin and colleagues have published several studies in leading medical journals arguing that the number of HIV/AIDS victims in India, and other parts of the world, are actually less than stated.