BUENOS AIRES, Argentina (Reuters) -- Police have arrested a man believed to
                  be a former member of Argentina's military intelligence in the 1974 car bomb
                  killing of Chile's former army chief, news reports said on Monday.

                  Juan Ciga Correa was detained in a Buenos Aires suburb on Sunday on suspicion
                  of having cooperated with the feared National Intelligence Department, or DINA
                  -- the secret service of former Chilean dictator Gen. Augusto Pinochet -- in the
                  murder of the exiled Gen. Carlos Prats.

                  Argentina was a democracy when Prats and his wife Sofia Cuthbert died on a
                  quiet residential street, but Argentine investigators believe the country's military
                  was already cooperating with repressive regimes elsewhere in the region.

                  Judge Maria Servini de Cubria interviewed Ciga Correa on Monday, according to
                  the private DyN news agency. She was not available for comment.

                  Ciga Correa was found in possession of a credential issued by the State
                  Intelligence Department.

                  Prats served loyally as army chief under Chile's Socialist President Salvador
                  Allende, but was replaced by Pinochet just weeks before Pinochet's bloody coup
                  of 1973. Prats went into exile in Argentina.

                  Servini de Cubria will decide soon whether to try to take testimony from
                  Pinochet, who is in Chile awaiting a local court decision on whether he can stand
                  trial there for atrocities during his 17-year rule.

                  In the 1970s, South America's dictatorships set up what became known as
                  "Operation Condor" to track dissidents who had fled their home countries. After
                  1976, when a coup began seven years of military dictatorship in Argentina,
                  Argentines hiding abroad were also hunted and killed with the help of the
                  countries in which they had sought refuge.

                  Secret police files uncovered in Paraguay in the early 1990s showed Operation
                  Condor was a Chilean idea. It attracted support from Argentina, Paraguay,
                  Uruguay, Bolivia and Brazil.

                  Two of Pinochet's most trusted aides, including former DINA chief Manuel
                  Contreras, have already testified to Servini de Cubria. So has American citizen
                  Michael Townley, the man suspected of planting the remote-control car bomb
                  that blew up Prats and his wife.

                  Servini de Cubria is also investigating accusations by Contreras that America's
                  CIA played a part.

                  One other man is under arrest in the case. Former Chilean agent Arancibia Clavel
                  was detained in Argentina in 1996 and will soon be put on trial.

                  Servini de Cubria last week called for protection after threats against her and her
                  staff over a separate investigation into theft of babies during the 1976-83
                  dictatorship.