Brazil's dictatorship is increasingly thought to have played a major role in Operation Condor, as one of the first military regimes installed in the region.

BBC: Brazil probes human rights atrocities

He is slated to film at least three other movies - including an action adventure, Operation Condor 3 - before work on Art of War is set to begin.

BBC: Jackie Chan in Rush Hour

The clandestine nature of Operation Condor means that its full extent may never be known, but researchers estimate that 50, 000 were killed, 30, 000 were "disappeared" and presumed killed, and 400, 000 were jailed, according to The Center for Justice and Accountability.

CNN: Trial over terrifying 'Operation Condor' under way