Alberto Nisman was investigating the 1994 bombing of a Jewish centre in Buenos Aires in which 85 people died.
On January 14, he accused Cristina Fernandez de Kirchner of involvement in a plot to cover up Iran’s alleged role in the bombing.
The president’s spokesman dismissed the allegations as “ridiculous”.
Alberto Nisman, 51, was found dead by his mother in the bathroom of his home.
The Security Ministry released a statement saying that Alberto Nisman’s bodyguards had raised the alarm after he failed to answer their phone calls on January 18.
Concerned about his welfare, they fetched Alberto Nisman’s mother and tried to enter his apartment, the statement said.
They found the door locked from the inside with a key still stuck inside.
After a locksmith gained access, they found Alberto Nisman’s body in the bathroom.
According to the statement, a gun and a cartridge shell were found next to his body.
Alberto Nisman was due to give evidence at a congressional committee hearing on January 19 to outline his accusations against President Cristina Fernandez de Kirchner and other officials.
He had published a 300-page report on January 14 alleging that the president and Foreign Minister Hector Timerman had opened a secret back channel to Iranians suspected of involvement in the bombing of the community centre.
Alberto Nisman alleged that the scheme was intended to clear the Iranian suspects in order to facilitate a trade deal between Iran and Argentina.
He said that he had issued a request that a judge question the president and the foreign minister “for being authors and accomplices of an aggravated cover-up and obstruction of justice regarding the Iranians accused of the AMIA [Israeli-Argentine Mutual Association] terrorist attack”.
The car bombing of the seven-storey building was the worst terrorist attack in Argentina’s history.
In 2007, Argentine prosecutors accused Iran of planning and financing the attack, and the Lebanese militant group Hezbollah of carrying it out.
Iran dismissed the allegations as “baseless”.
So far, no-one has been convicted in connection with the AMIA attack.
Last July, at events marking the 20th anniversary of the bombing, Pope Francis demanded justice for the victims.
6t3UxT3i7Q8Image source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…