Asvat's brother, Ibrahim, was testifying in Johannesburg on the sixth day of hearings into the alleged reign of terror - including acts of murder, kidnapping and assualt - conducted in Soweto in the late 1980s by President Mandela's former wife, Winnie Madikizela-Mandela, and her personal bodyguard, the now defunct Mandela Football Club.
The hearing is being chaired by Archbishop Desmond Tutu.
In one sensational allegation, one of Asvat's convicted killers, Cyril Mbatha, has claimed that Madikizela-Mandela had paid him R20,000 for the killing and provided the firearm.
On Monday, Asvat said: "We and Mrs Madikizela-Manela want these allegations to be put to rest finally."
He added: "The TRC is the only forum that can provide us with answers."
Asvat repeated that the family had never accepted that the motive for the murder was robbery.
He said that at the conclusion of the trail of people accused his brother's death, the prosecutor had shown him and his attorney a statement made by one of the co-accused, a Thulani Dlamini, that "Mandela had paid him an amount of R20,000 and provided the weapon".
"The prosecutor said police investigators did not want to pursue this. He said this particular statement may become helpful sometime in the future," Asvat said.
Asvat said they did not believe the motive of robbery as money had been found in huis brother's consulting rooms after ther murder and his brother still had his gun strapped to his leg.