Angry campaigners on Tuesday said India's health minister was hampering the fight against AIDS after he branded homosexuality a "disease" which had been introduced to the country by foreigners.
The International AIDS Society, which organises the world's AIDS conferences, blasted the remarks as "irresponsible (and) homophobic."
"(They) are a sad testament to how far the world still has to go to before its gay, lesbian and transgender citizens can enjoy the same health care and human rights as the rest of the population," Bertrand Audoin, the IAS executive director, told AFP.
"Such comments can serve only to negatively impact the lives of gay people who already struggle with inherent discrimination," he warned.
Stigma "places significant obstacles in the path of effective HIV/AIDS prevention efforts by driving gay people away from the HIV prevention, treatment and care that some of them desperately need," Audoin said.
The UN agency UNAIDS issued a statement from the sidelines of the meeting in New Delhi where Health Minister Ghulam Nabi Azad made the controversial remarks.
UNAIDS did not mention Azad by name, but pointedly said it "rejects prejudice and misconceptions" about men who have sex with men.
"UNAIDS does not regard homosexuality as a disease," its executive director, Michel Sidibe, said.
He pointed to UN guidelines -- published just two weeks earlier -- that calls on countries to implement laws which protect gays and transgender people from discrimination and violence.
Azad, speaking at a national meeting of district and mayoral leaders on HIV/AIDS prevention, declared homosexuality to be "unnatural and not good for India".
"It is a disease which has come from other countries," he added.
"Even though it is unnatural, it exists in our country and is now fast spreading, making it tough to detect it."
Britain's leading HIV and sexual health charity, the Terrence Higgins Trust, said Azad was ironically "perpetuating the anti-gay prejudice" of India's colonial rulers.
"Same-sex activity is celebrated in many historical texts and paintings of Indian origin, but anti-gay laws were brought in by the British in 1860," observed Lisa Power, the trust's policy director.
"UNAIDS has made it clear that anti-gay prejudice and discrimination makes it harder for a country to successfully combat HIV, so the minister needs both a history lesson and a health promotion one."
The controversy brewed almost two years to the day after the Delhi High Court scrapped colonial-era laws against "carnal intercourse against the order of nature." Conviction carried a fine and maximum 10-year jail sentence.
It comes just weeks after the 30th anniversary of the AIDS epidemic, where the world's nations recommitted themselves to fighting the disease, including discrimination.
AIDS campaigners say groups such as homosexuals, sex workers, intravenous drug users and prison inmates are highly vulnerable to the spread of human immunodeficiency virus (HIV).
Criminalising or stigmatising such groups helps HIV spread swiftly within these social niches and then leap out into the wider population, they say.
It was on June 4 1981 that the first cases of what would be called acquired immune deficiency syndrome (AIDS), a disease that wrecks the body's defences and opens the way to opportunistic infection, were first noted among American homosexuals.
Within a short time, HIV was found to be transmissible to heterosexuals too, through sexual intercourse and blood transfusions and from an infected mother to her foetus.
Around 30 million people have died of AIDS since 1981 and 33.3 million live with HIV, UNAIDS said in a report last year.