A Chilean judge ruled Monday that former President Eduardo Frei Montalva was assassinated nearly 30 years ago and his killing covered up by people linked to the dictatorship of Gen. Augusto Pinochet. Six people were charged in the case.
Frei, who preceded Salvador Allende as Chile's president and later became a leading critic of the military dictatorship, died in 1982.
An autopsy report blamed septic shock after stomach hernia surgery, but a new autopsy this year by University of Chile pathologists identified two chemicals in his body that attack the digestive system _ one that is used in mustard gas and another found in rat poison.
"He was injected with toxic substances, which produced other complications that deteriorated his immune system," Judge Alejandro Madrid told reporters Monday. "That was the cause of death."
At the time of his death, Frei, 71, was investigating human rights violations by the dictatorship of Pinochet, who toppled Allende in a 1973 coup.
"This goes to show that though it may take a while, justice in Chile always prevails," President Michelle Bachelet said of the judge's ruling.
Madrid filed murder charges against one of Frei's doctors who was involved in the surgery, Frei's driver and a civilian army employee. A second doctor was charged as an accomplice, and two Catholic University pathologists who conducted the initial autopsy were accused of covering up the killing.
The case was raised nearly a decade ago by the Frei family after a Belgian university investigation found mustard gas in Frei's body. His son Eduardo Frei Ruiz-Tagle, who was president from 1994 to 2000 and is running for a second term in elections Sunday, has said justice is long overdue in his father's death.
"We want to invite other families to seek the truth and get justice for what happened to their loved ones," Frei said, referring to the family members of those killed during the dictatorship.
The slain man's daughter, former Sen. Carmen Frei, also welcomed the judge's findings. "Today is very hard, but we are very satisfied. It is a historic step," she said.
Pinochet ruled Chile until 1990 and died in 2006 without having stood trial for abuses during his dictatorship.