A woman holds up a sign that reads "Justice" during a demontration to demand justice over the death of Argentine prosecutor Alberto Nisman in front of the Casa Rosada Presidential Palace in Buenos Aires January 26, 2015. [Photo/Agencies]

Nisman, 51, was found dead Jan. 18 in the bathroom in his apartment, a bullet in his right temple. A 22 caliber gun was found next to him. His death came days after he gave a judge a report alleging Fernandez secretly reached a deal to prevent prosecution of former Iranian officials accused of involvement in the 1994 bombing of Argentina's largest Jewish center, which killed 85 people. She allegedly reached the deal in exchange for economic and trade benefits with Iran.

Iran has denied the accusation.

Nisman's death has produced anti-government protests and a myriad of conspiracy theories, ranging from suicide to the involvement of Iranian intelligence agents.

Appearing rested and calm, Fernandez began with a spirited defense of all her government had done to try to solve the 1994 case.

She lamented that more than 20 years later nobody had been convicted or even detained. She noted that her predecessor, husband and former President Nestor Kirchner, had appointed Nisman to the case after years of paralysis.

She said a 2013 memorandum of understanding with Iran, which many in the country have bitterly criticized, was aimed at obtaining cooperation with the Middle Eastern powerhouse to finally seek justice for the bombing.