Brazilian authorities on Wednesday exhumed the remains of former President Joao Goulart to determine if he was murdered as part of Operation Condor, a collaboration among various South American military regimes to eliminate their respective political foes.

The former left-leaning president, popularly known as "Jango," was overthrown in a 1964 military coup with the U.S. government's blessing and died in exile in 1976 in Argentina.

"Modern techniques can reveal results and lead to conclusions, but let's let the experts do their work and I hope they can arrive at the truth," Brazilian Justice Minister Jose Eduardo Cardozo, who was on hand for the exhumation at the cemetery in the southern city of São Borja, said.

The goal is to determine if Goulart was murdered on orders from Brazil's 1964-1985 military regime as part of Operation Condor, which coordinated anti-dissident efforts among the military regimes of Chile, Argentina, Uruguay, Brazil, Paraguay and Bolivia in the 1970s and early 1980s.

The ousted president, who had a history of heart problems, died in 1976 at a hotel in Mercedes, Argentina.

The official cause of death was a heart attack, but authorities in Argentina and Brazil - where Goulart was buried - prevented an autopsy.

Around five years ago, a former Uruguayan spy serving a prison sentence in Brazil for arms smuggling came forward to say that Goulart was poisoned.

Mario Neira Barreiro said Uruguayan intelligence operatives killed Goulart by replacing his normal heart medication "with pills having a contrary effect."

Goulart's remains will be transferred Thursday to Brasilia, where a forensic exam will be conducted.

They will be received in Brasilia will full honors at a ceremony including President Dilma Rousseff and several of her predecessors.