David Rasnick, a California-based scientist and Aids dissident, has challenged Costa Gazi, the South African public health doctor, to a potentially lethal public experiment.
In a letter in the Mail & Guardian on Friday, he said this was in line with an offer he had made several times before, but which no one had accepted.
"On national or international television I will be treated with purified, infectious HIV. At the same time Costa Gazi will begin a lifetime course of the three-drug cocktail known as Haart.
"The experiment is simple: we will see who comes down with Aids-defining diseases and who lives longer," Dr Rasnick said.
People who suggested that President Thabo Mbeki infect himself with HIV were willing to risk the president's life to make their point.
"I am willing to risk the life of a mainstream proponent (Gazi) of the contagious, HIV hypothesis of Aids who is eager to give AZT to pregnant women and their babies," he said.
Dr Rasnick and his colleague, Peter Duesberg, are proponents of the view that Aids is not caused by HIV.
The men, both on President Mbeki's Aids Advisory Panel, say AZT is toxic and "drugs cause Aids".
"Aids is preventable by banning anti-HIV drugs and by advertising the medical consequence of recreational drugs," they said in a 1997 paper.
They argue that AZT not only failed to prevent Aids, but actually causes Aids diseases and accelerates death.
Dr Gazi, who is also the PAC's secretary for health, described Dr Rasnick's challenge as absurd.
"It is based on a series of false premises. It is an astonishing gesture that will prove nothing whatsoever if it had to be carried out."
Dr Gazi said he had never challenged Mbeki to inject himself with HIV, and that Dr Rasnick had confused him with some other mainstream scientist.
"My criticism of the president's confusion has been based on his actions and statements and the dire consequences of his policies.
"It would never have crossed my mind to have asked him to subject himself to such a dangerous procedure."
Dr Gazi said it would be unethical to expect anyone to expose themselves to clearly damaging procedures.
"It has been known for over 15 years that persons infected with HIV will indubitably develop Aids and die of Aids-related diseases - unless of course they have access to anti-retroviral therapy such as Haart.
"In countries where such therapy is available, Aids no longer has lethal consequences but has joined the ranks of chronic diseases which require regular medication."
Dr Gazi said it was well known that all drugs that were useful in medicine could also cause harm. The trick was to balance the harm done against the good.
At present the only direct assault that was available on HIV, were anti-retrovirals, he said.
"They do have toxic side-effects, but they are no different in that regard from an antibiotic."
It should be remembered that HIV was a very dangerous infection, Dr Gazi said.
"It would be stupid for me to take a drug that I do not need. However, it would be very sensible for him to inject himself with a virus that he has been incessantly claiming is an innocent bystander and does not cause Aids."
Dr Gazi said his support for the use of AZT, and latterly nevirapine, was based on mountains of evidence that the drugs would significantly reduce the chances of an HIV-positive mother passing the virus on to her baby.
"My concern is not to promote such drugs but to save lives."
Dr Rasnick and his fellow thinkers had been trapped in a time warp for 15 years, Dr Gazi said. - Sapa