The Inkatha Freedom Party has called on the South African Human's Right Commission (SAHRC) to launch an urgent investigation into the Department of Correctional Services and the minister, Ngconde Balfour.
IFP spokesman Sybil Seaton said Balfour is guilty of human rights abuses.
The call and accusation follow a television programme which showed disturbing scenes of sick and dying inmates being left to waste away behind prison walls.
The IFP believes that Balfour should be held accountable for the "horrible scenes in prisons".
"Access to basic medical care inside our prisons, or lack thereof, is an issue that has been discussed at length before in Parliament's portfolio committee on correctional services," Seaton said.
"But I don't think any of us fully realised the extent of the crisis that we are facing."
Previously, the IFP said that health care in most prisons was in crisis.
"The Bill of Rights affords [everyone] the right to all basic medical care and clearly Correctional Services is in violation of this basic human right," Seaton said.
"We therefore call the commission to launch an urgent investigation into this matter."
SAHRC spokesman Vincent Moaga said they were talking to the IFP.
"We believe that all sick inmates should be given a chance for medical parole to die in a dignified way."