Chile's Supreme Court is to rule next week on an appeal by former military ruler Augusto Pinochet against lifting his immunity from prosecution.
Gen Pinochet has so far avoided prosecution
The court heard arguments from prosecutors and defence lawyers in a three-hour session on Wednesday.
Gen Pinochet is accused of involvement in abducting and killing political prisoners in what was known as Operation Colombo.
Defence lawyers say Gen Pinochet - who ruled from 1973 to 1990 - is innocent.
The appeal follows a ruling by another court in July that Gen Pinochet could faces charges in a human rights case.
The 89-year-old former leader is accused of being involved in a Chilean secret police operation in 1975 in which 119 left-wing activists disappeared.
The case being presented against him specifically mentions the abduction and disappearance of 16 of these activists.
At the time, his government said the dissidents had been killed in Argentina, in clashes involving rival groups opposed to the military government.
Despite several high-profile legal cases against him, the former president has so far managed to avoid prosecution, mostly on grounds of ill-health.
Human rights campaigners have accused the general of exaggerating his health problems to try to win the sympathy of the courts.
Gen Pinochet has also been stripped of the immunity he enjoys as a former ruler to allow an inquiry into his financial affairs. An appeal against that ruling has yet to be heard by the Supreme Court.