Chemical weapons were used against Unita rebels during the war in Angola, the Health Professions' Council of SA heard yesterday.
The council's professional conduct committee is holding a hearing into allegations of unethical conduct against Cape Town cardiologist Wouter Basson.
Salie Joubert SC, representing the council, asked witness Dr Niel Knobel, a former SA Defence Force surgeon-general, whether it was his testimony that chemical weapons were used against Unita forces in Angola.
"Based on our own reports, although I was not personally involved in some of those incidents, South African troops who were deployed with Unita were often called to come forward to come and give assistance to members of Unita that were exposed to some or other chemical substance," said Knobel.
"The evidence that we have from the reports given by generals and commanding officers of that operation, all of them reported that there were bombs released by fighters, a lot of smoke was coming down and it affected a lot of the troops," he said.
The charges against Basson arise from his involvement in the apartheid government's chemical and biological warfare programme in the 1980s and early 1990s.
He is accused of acting unethically by being involved in the large-scale production of Mandrax, cocaine and teargas, of weaponising teargas, and of supplying it to Unita leader Jonas Savimbi.
He is also accused of acting unethically by providing disorientating substances for cross-border kidnappings, and making cyanide capsules available for distribution to operatives for use in committing suicide.
During cross-examination yesterday, Joubert asked Knobel about details of meetings he had with former president Nelson Mandela when he was still in office.
He refused and said the meetings were confidential.
"Joubert is starting to question me on meetings I had with Mandela, which I am not at liberty to discuss," he said.
However, Knobel confirmed that Mandela had rejected calls by the UK and the US to prevent Basson from travelling abroad.
In 2002, Basson was acquitted by the Pretoria High Court of charges arising from his conduct.
The council reviewed the judgment to establish if there were grounds to continue with an inquiry against him.
The state lost its Supreme Court of Appeal bid and a Constitutional Court application in September 2005.
In 2007, the council investigated Basson's conduct.
However, the inquiry was delayed when the council's main expert witness fell ill. It resumed in 2008.
During the November 2008 hearing, Basson's legal team argued that the case brought against him was unlawful and biased.
Basson's legal team then went to the Pretoria High Court to stop the inquiry. The court dismissed his application in May 2010.
In January 2012, Basson brought an application before the council's professional conduct committee to dismiss the matter.
However, this application was also dismissed.