Darren Padayachee stabbed his 46-year-old father Benjamin Moodley to death following a domestic dispute, according to their neighbours in Phoenix, north of Durban.
Moodley had spent the last year reconciling with his family after spending 20 years in jail for a murder.
"We are really battling to come to terms with this incident," said Pdayachee's sister Richelle, at whose home the alleged murder took place.
Padayachee yesterday appeared before court which denied him the bail.
Also Read
She said Darren had been fighting with his girlfriend, known only as Andrea, when her father intervened.
The man allegedly stabbed his father in the heart and punctured his lung, but Padayachee said her brother was "a peaceful guy" and the stabbing was a "freak accident."
The family was getting ready to have a huge Father's Day celebration this weekend, but are now preparing for a funeral and court appearances.