BRASILIA, Brazil (Reuters) -- Brazil launched a landmark inquiry into its dark
                  military past on Wednesday amid accusations that dictators ordered the
                  kidnapping, torture and murder of leftist leaders and possibly a former Brazilian
                  president.

                  New documents, testimony and unprecedented government support met the
                  congressional probe at the start of hearings -- the first official attempt to shed
                  light on abuses during Brazil's 21-year military regime, which ended in 1985.

                  Lawmakers say information gathered from human rights groups Wednesday
                  proves Brazil helped form "Operation Condor" -- a scheme by South American
                  dictators to help each other hunt down political enemies hiding abroad.

                  "Official documents were provided to the commission today showing many
                  exchanges of prisoners with other countries... Argentina, Uruguay," said
                  Nilmario Miranda, who sits on the Human Rights Commission leading the
                  investigation. "What we know now is that Brazil not only had sporadic
                  involvement in Operation Condor, it had an expressive, institutionalized
                  involvement.".

                  Key to the inquiry will be a fresh investigation into whether ex-Brazilian President
                  Joao Goulart, deposed when the military came to power in 1964, was murdered
                  in his sleep while in exile in Argentina in 1976.

                  Miranda said Goulart's family -- who have long suspected foul play -- has given
                  a green light for an exhumation of the body of the fallen president, who officially
                  died from a heart attack. Miranda further appealed for the government to quickly
                  turn over all documents relating to Operation Condor to the investigation.

                  In an unprecedented move, Brazil's new, civilian-run Defense Ministry said it will
                  order all branches of the armed forces to search their archives for information
                  relating to extraterritorial military activities since 1964.

                  "The Navy, the Army and the Air Force will be ordered to turn over any
                  documents on this issue. All we are waiting for is a letter from the attorney
                  general, which should arrive tonight," a Defense Ministry spokeswoman said.

                  She added that while top brass who led Brazil's now-defunct National
                  Information Service -- much like the U.S. Central Intelligence Agency -- have
                  denied any knowledge of Operation Condor, "There are many other officers who
                  say their statements are false."

                  The investigation comes years after Brazil's neighbors, including Argentina and
                  Chile, began investigating atrocities under their respective military regimes,
                  which were much more severe than in Brazil. While hundreds of political
                  activists died in Brazil, more than 3,000 are thought to have been killed in Chile.
                  In Argentina, human rights groups say up to 30,000 people were killed or
                  "disappeared" at the hands of the military government.

                  Reports of Operation Condor first emerged in 1992, when a Paraguayan lawyer
                  uncovered the so-called "Archive of Terror" detailing Paraguay's illegal swap of
                  "disappeared" prisoners among South American nations during its dictatorship.
                  But as one of the first military regimes installed in the region, Brazil's dictatorship
                  is increasingly thought to have played a major role in Operation Condor.