Thousands of HIV-positive women could be denied a chance to save their babies' lives following a ruling which is likely to lead to the banning of the anti-Aids drug nevirapine.
The Medicines Control Council (MCC) informed the drug's manufacturer, Boehringer-Ingelheim, on Tuesday that it had rejected a Ugandan study on which the registration of nevirapine was based.
This means that, in the space of a week, nevirapine was endorsed by the World Health Organisation, but rejected by a body accused by some of succumbing to political influence.
Details from several studies confirming the results of the Ugandan research were compiled by leading scientists and submitted to the MCC in June.
But the council did not mention this evidence in its letter to Boehringer-Ingelheim, which requested additional information within 90 days proving the drug's safety and efficacy.
Once the 90-day period is over, doctors could be forbidden from using nevirapine to prevent HIV-positive pregnant women from passing the virus on to their babies.
The drug will, however, still be available because it will remain registered for lifelong use in people who are already infected.
But doctors using it to save babies' lives risk being criminally charged for their actions, fined and jailed for up to 10 years.
Kevin McKenna, spokesperson for Boehringer-Ingelheim, said his company would try to work with the MCC and "eradicate their concerns".
"It just sounds absolutely unbelievable," said Dr Tammy Meyers, a paediatrician involved in a study at Coronation Hospital in Johannesburg, which has confirmed the Ugandan evidence.
Professor James McIntyre, co-director of the Perinatal HIV Research Unit, where other studies have also backed up the Ugandans, said there was also evidence from government hospitals and clinics.
"The experience of other trials and many other women, probably in excess of 50 000 around the world, have demonstrated the efficacy and safety of Nevirapine (in reducing maternal transmission)," he said.
The Ugandan study was the first to prove that a single dose of nevirapine to a woman in labour, followed by a few drops to her newborn baby, halved HIV transmission from mother to child.
Results from the study were questioned by American authorities last year, after concerns were raised about administrative procedures during the research.
An investigation conducted by US officials revealed that, while there were minor administrative problems during the trial, there was no reason to doubt the results.
The US submitted a detailed report on the investigation results to the MCC.
Internationally renowned paediatrician Professor Hoosen "Jerry" Coovadia said of the MCC's decision: "I think this is just such a dreadful mistake."
"The implications for the country's programme to prevent mother-to-child transmission, and for the reputation of our country, are really very profound," he said.
"I think we are now going back to the stage from which we thought we had advanced - that is, all the controversy around HIV/Aids.
"I've read the (American) report, and I didn't need anything else. The conclusions of the report were that there was no question about the scientific validity of the findings. That means the safety and efficacy of the trial was not questioned - in fact it was confirmed."