A judge has interrogated former Chilean President Augusto Pinochet about allegations of human rights abuses during his 17-year military rule.
Gen Pinochet has said he had no knowledge of the killings
The interview came a month after Gen Pinochet lost his legal immunity.
Judge Juan Guzman asked him about a campaign by South American military governments to kill their opponents in the 1970s and 1980s.
Defence lawyers say the 88-year-old general is too ill to stand trial or even be questioned.
However, one of them, Gustavo Collado, was quoted by the Associated Press news agency as saying he had been able to answer all the questions put to him "with dignity".
Investigating judge Juan Guzman, who has attempted to prosecute Gen Pinochet for years, visited him at his home for about an hour on Saturday.
Court sources said the interview focused on the knowledge Gen Pinochet may have had of the kidnapping and torture of some 19 Chileans in Operation Condor.
KEY DATES IN PINOCHET'S LIFE
1973: Leads coup against left-wing President Salvador Allende
1988: Loses plebiscite on rule
1990: Steps down as president
1998: Retires as army commander-in-chief. Arrested in UK at Spain's request
2000: Allowed to return to Chile
2004: Supreme Court strips his legal immunity
This was a co-ordinated campaign by the military governments in the region to track down, interrogate and kill left-wing opponents.
Last month Chile's Supreme Court stripped the former president of his legal protection, raising the possibility he could be put on trial for the first time.
The BBC's Clinton Porteous in Santiago says the formal questioning is another step in that direction.
Judge Guzman will decide what happens next, but many believe he will order fresh medical tests on Gen Pinochet, our correspondent adds.
Alternatively, the judge could decide to indict him.
Mr Guzman indicted Gen Pinochet in a different human rights case in 2001, but on that occasion the country's Supreme Court declared him unfit to stand trial.
He has been diagnosed with a mild case of dementia and suffers from diabetes and arthritis.
His lawyer, Mr Collado, said Gen Pinochet was "very tired" after Saturday's questioning, and required medical attention.
In a recent interview with a Miami television station, the former military ruler appeared lucid and blamed subordinates for the abuses carried out by his regime.