Professor Jeff Wing told Sapa Tshabalala-Msimang died in the Wits University Donald Gordon Medical Centre and Medi-Clinic ICU "about a minute ago", shortly before 3pm.
He said she died from complications related to her first liver transplant in 2007.
After the transplant she received from a teenage suicide victim, controversy erupted when the Sunday Times reported that the cirrhosis that necessitated her liver transplant was alcohol-induced.
It also alleged that Tshabalala-Msimang had continued drinking alcohol even after receiving a new liver.
* Sapa
