Former DA leader Tony Leon's father, Ramon Leon, died at the weekend, his office confirmed on Monday.
"A memorial service will be held for Judge Leon this Thursday in Durban," one of his staffers said in an e-mail.
No further details were given.
Ramon Leon was an apartheid-era judge who served on the Natal Bench for over 20 years.
He sentenced Andrew Zondo to death for his role in a blast that killed three adults and two children in an Amanzimtoti shopping centre in 1985.
The bomb was in response to an SA Defence Force raid on Maseru, Lesotho, a few days earlier in which nine people were killed.
Zondo was hanged less than nine months after the bombing.
Leon Senior served in other roles, including chairing a Lesotho commission of enquiry into the causes of political violence in 1998.