Ivan passed away on Thursday morning at a hospital in Pretoria where he had been admitted following a heart attack early last week.
“You have touched and helped thousands, you did wonders.” She said.
Semwanga owns schools and other businesses in South Africa.
In Uganda, Semwanga was known for his generosity; making huge financial contributions to charity organizations and to the needy in the society.
He once donated funds to the Uganda Cranes, supporting the national football team during critical moments.
Many of his fans saw him as a role model due to his selflessness and humility.
He was last spotted at in public at a Blankets and Wine event at Lugogo Cricket Oval, Uganda before returning to South Africa.
Zari said he was a “hero-some kind of superman” to their three sons.