The former Chilean military ruler, General Augusto Pinochet, is recovering in hospital after fainting over breakfast, doctors say.
Augusto Pinochet has suffered health problems in the past
They said the 89-year-old was "stable" and would remain in Santiago's military hospital for observation.
Gen Pinochet's family said earlier he had suffered a stroke, but it is not clear how serious the problem was.
The Chilean Appeal Court was to begin considering on Wednesday whether to strip him of his legal immunity.
If this happens, he could be prosecuted over a secret operation in which more than 100 left-wing activists disappeared.
Lawyers for Gen Pinochet insist on his innocence in the case, known as Operation Colombo.
The former leader was treated in hospital last month after suffering what aides said was a suspected mild stroke.
Gen Pinochet's opponents have previously questioned the timing of his bouts of ill-health, saying they usually coincide with imminent court appearances.
The general's son, Marco Antonio Pinochet, told reporters outside the hospital earlier on Tuesday that his father was semi-conscious and was under observation.
"I wasn't there but my mother said he was eating breakfast when he fainted and lost consciousness for 30 minutes," he said, according to Reuters news agency.
He denied there was a link between the medical crises and the case against his father.
"My father these days is not conscious of what's going on with his legal situation. The truth is that he isn't affected by what's going on in the courts. What affects him is his illness," Mr Pinochet said.
Gen Pinochet has never been put on trial for human rights violations under his 1973-90 rule, despite several high-profile cases against him.
A Chilean court recently ruled that the general was not mentally fit enough to be prosecuted over Operation Condor - a joint campaign by as many as six South American regimes to hunt down and kill their opponents.
However, the same court stripped him of the immunity from prosecution he enjoys as a former president, allowing an inquiry into his financial affairs to go forward.