Pistorius family patriarch, Hendrik Pistorius, died in the early hours of Friday morning, at the age of 101.
Oupi, as his loved ones called him, was the father of seven children, grandfather to 25 grandchildren and had 35 great-grandchildren - including disgraced Paralympic athlete Oscar Pistorius and his brother and sister, Carl and Aimee.
Speaking to YOU from China on Friday, Leo Pistorius, Oupi's youngest son, said the centenarian was admitted to a private hospital in Pretoria a few days ago for a minor operation. He died shortly after midnight on Friday morning.
"He was due to be discharged today. He was all set to accompany my sister and her family to the Kruger National Park yesterday (Thursday) and they'd had to move the reservation [because of the operation]."
Chuckling, Leo adds, "He was livid about it!"
He leaves behind four sons: Theo (73), Arnold (67), Leo (56) and Oscar's dad, Henke (65), and three daughters, Sonia Grobler (71), Heidi Drew (70), and Reine Malan (62).
'Most optimistic person I knew'
Oupi's wife, Gerti, died in October 2016 at the age of 92. They'd been married for almost 75 years.
"My father was the most optimistic person I knew," Leo tells us.
For his birthday on August 29, his loved ones had treated him to a meal at his son Theo's restaurant, Relish Bistro, in Pretoria.
"We spoilt him with his favourites, such as biltong, dried fruit, cheeses, olives and a glass of good chenin blanc," Heidi told us at the time. "At this age possessions aren't important anymore."
Oscar (31), who's serving a 13-year jail sentence for murdering his girlfriend Reeva Steenkamp on Valentine's Day 2013, was unable to attend his grandfather's last birthday.
Oupi visited his grandson at the end of last year during the prison's open day. Apparently Oscar had been touched by his grandfather's visit and became emotional.
When YOU spoke to Oupi shortly after his birthday this year, he became visibly sad when speaking about Oscar.
His eyes had welled up when he said, "I cried deep inside me. My grandson isn't a murderer - he's a gentleman. Gentle, but a man."