The U.S.-based rights group said the men, all arrested since October, were given HIV tests without their consent. Two were also subjected to forensic anal tests to look for evidence of homosexual conduct, which the group said amounted to torture.

Three men, whom Human Rights Watch said had reportedly tested HIV-positive, were being held in hospital handcuffed to their beds and "only unchained for an hour each day".

"These cases show Egyptian police acting on the dangerous belief that HIV is not a condition to be treated but a crime to be punished," Scott Long, who works on gay rights issues at Human Rights Watch, said in a statement.

"Egypt threatens not just its international reputation but its own population if it responds to the HIV/AIDS epidemic with prison terms instead of prevention and care," he said.

The Interior Ministry had no immediate comment.

Human Rights Watch said the arrests began after police stopped two men having an altercation on a Cairo street in October 2007. One told police he was HIV-positive, prompting an investigation against both for homosexual conduct.

Police later arrested two additional men whose pictures or phone numbers were found on the first two detainees, as well as four others who took over the lease of an apartment where one of the previous detainees had lived, the group said.

Human Rights Watch said the first four men remained in detention pending a decision on whether to charge them with homosexual conduct. The other four were tried and convicted of habitual debauchery, which Human Rights Watch says is used to penalise homosexual contact, and sentenced to a year in jail.

"The government should end arbitrary arrests based on HIV status and take steps to end prejudice and misinformation about HIV/AIDS," the Human Rights Watch statement said.

Human Rights Watch said it had received reports that the second group of four were forced to stand in a painful position for three hours with their arms raised, and were given no food, drink or blankets during their first four days in detention.

One was reported to have been beaten on the head by a non-commissioned officer, the group said.

According to a 2004 study, the majority of Egypt's health workers believe those with HIV should be removed from society, while most university students think "lewd" people or those with "neither values nor principles" are likeliest to get AIDS.

But Egypt has also made progress in combating the spread of HIV. Since 2004, testing for Egyptian nationals has been anonymous, and the Health Ministry has made HIV drugs available free of charge since 2005.