Wyre Davies investigates the mysterious death of Alberto Nisman, the special prosecutor who had accused Argentina’s government of trying to cover up the deadliest terror attack in the country’s history. Hundreds of thousands of people have taken to the streets of Buenos Aires, demanding to know how and why he died. The issue is dominating President Cristina Fernandez de Kirchner’s final year in office. Nisman was found dead, with a gun by his body, the night before he was due to testify about the alleged cover-up in Congress. Was it suicide or was it murder?

Produced by Sarah Robbins and Arlene Gregorius

(Photo: Demonstrators hold up images of late Argentine prosecutor Alberto Nisman in front of the Justice Palace in Buenos Aires, March 18, 2015. Credit to: REUTERS/Marcos Brindicci)