Abu Baker Asvat, allegedly because he had seen the badly beaten Stompie shortly before the teenager died and had refused to corroborate her story.
Mbatha broke down and wept, begging forgiveness from the Asvat family.
Cyril Mbatha, 29, said Winnie gave him the gun to shoot dead Abu-Baker Asvat telling him it would be for the "cause of our country.
Yesterday Mbatha, who is serving life for the killing, wept as he asked for the Asvat family's forgiveness.
Winnie tambien ha sido acusada de asesinar al medico Abu Baker Asvat
, quien intento salvar la vida de Sepei.
But Kosogi et al  and Asvat
et al  stated that there are no clear gender and racial differences in the occurrence of supernumerary head of biceps.
She also denied claims by former football club member Katiza Cebekhulu that she plunged a "shiny object" into Stompie and ordered the killing of Soweto doctor Abu-Baker Asvat.
She branded Cebekhulu a "mental patient" and said Asvat was a "close friend" whose death had shocked and saddened her.
And he claimed she offered him pounds 5000 to shoot Dr Abu-Baker Asvat.
Mbatha told the hearing: "Mrs Mandela said if we killed Dr Asvat we would be paid pounds 5000 and maybe more.