Ngqumba said the TRC's amnesty committee had run out of time to hear Mamasela's evidence. He was now expected to testify when the hearing, which was due to adjourn on Friday, resumed next March.
Mamasela arrived in Port Elizabeth on Wednesday and was reportedly being kept in a safe house while waiting to be called to testify.
He was subpoenaed to give evidence about his role in the 1985 abduction and murder of Port Elizabeth activists Sipho Hashe, Champion Galela and Qaqawuli Godolozi.
Seven former security policemen and an askari (turned Umkhonto we Sizwe guerilla) have applied for amnesty for their involvement in the clandestine operation to eliminate the three.
The applicants are former Port Elizabeth security policemen Colonel Gideon Nieuwoudt, Gehardus Lotz, Colonel Herman du Plessis, Captain Sakkie van Zyl and Colonel Harold Snyman, Vlakplaas operatives Gert Beeslaar and Johannes Koole and askari Peter Mogoai.
During the two-week hearing the amnesty committee has heard how the three men were kidnapped by security police after being lured to Port Elizabeth airport by an informer posing as a member of the British embassy.
The committee was told the activists were taken to Post Chalmers, a disused police station near Cradock where they were interrogated and then shot. Their bodies were placed on a pile of wood, doused with diesel and set alight. The burnt remains were thrown into the Fish River.
However, Mamasela has told TRC investigators and the Transvaal Attorney-General's office a different story.
He maintains that the Pebco Three were not shot but beaten to death during interrogation. Their bodies were then removed from the scene of the murders.
His version of events is partially corroborated by two of the applicants, Koole and Mogoai, who have admitted beating several of the activists at Post Chalmers.
However, Nieuwoudt and the other former Port Elizabeth security policemen have denied any assaults took place.