A keynote speaker from South Africa at the International Aids Conference in Toronto, Canada, has called on South Africa's health minister to resign.
Tshabalala-Msimang has endorsed controversial responses to Aids
Mark Heywood, head of the Aids Law Project in South Africa, said Manto Tshabalala-Msimang had minimised the role of anti-retroviral drugs.
The governing ANC party said the remarks were "unacceptable".
The minister said this week she wanted to give citizens choices, including traditional treatments.
"A minister tells people about garlic and lemons, but doesn't tell people about anti-retroviral medicines," Mr Heywood told delegates - a reference to certain foodstuffs that the South African government has promoted as being useful for Aids patients.
"People who follow her advice in late-stage HIV infection and take garlic and lemons will die," Mr Heywood continued.
"People who take anti-retrovirals in late-stage HIV infection will return to health."
Lemons and garlic were among the items displayed alongside anti-retroviral drugs (ARVs) and condoms at South Africa's exhibition at the International Aids Conference in Toronto.
Dr Tshabalala-Msimang has not responded directly to Mr Heywood's remarks, but the ANC came to her defence in a statement issued on Friday.
"Whatever criticisms they may have of South Africa's policies on HIV and Aids, they have no right to personalise these policies," the statement said.
"The ANC reaffirms its support for government's comprehensive plan for management, care and treatment of HIV and Aids, and for an approach that aims to combat HIV and Aids in an all-embracing and integrated manner."
The Treatment Action Campaign (TAC) - which works closely with the Aids Law Project - said in a statement it would announce plans on Friday "to ensure that the health minister is sacked tomorrow".
The vital ARV treatment came too late, say the TAC
TAC said it was meeting officials from South Africa's Human Rights Commission, after learning that a prisoner identified as "MM" had died two weeks ago.
"MM" was one of 15 HIV-positive inmates at Westville Prison in Durban who won a court case ordering the prison authorities to supply them with ARV medication.
The government appealed against the ruling, and TAC says the delay in supplying ARV drugs led to the prisoner's death.
After pressure from activists, South Africa changed its policy and started distributing ARVs at government clinics in 2004.
The government currently gives ARVs to over 100,000 of the approximately 6m South Africans who are HIV-positive.