Manga, 56, contracted double pneumonia this week and had also been suffering from colon cancer, according to the public broadcaster.
He died in the Donald Gordon Medical Centre in Parktown.
Manga worked for the SABC for 7½ years, in various positions including national television editor and head of television news.
He also worked for the Rand Daily Mail, New Nation and Sowetan newspapers.
He leaves behind his wife and daughter, according to the report.
Manga was reportedly a casualty of a purge by SABC news head Phil Molefe at the beginning of 2011, when he was moved from his position as head of television news to the position of economics editor.
The Sunday Times reported at the time that the move was a drive by Molefe to remove editors appointed by his predecessor, Snuki Zikalala.