BUENOS AIRES, March 5 (Reuters) - Independent forensic tests show the Argentine state prosecutor found dead days after he accused President Cristina Fernandez of plotting to cover up Iran's alleged role in a 1994 bombing was murdered, the deceased prosecutor's ex-wife said on Thursday. Argentine authorities have not released full results of the autopsy of Alberto Nisman, who was found in a pool of blood with a bullet to the head on Jan.