An Argentine prosecutor who accused President Cristina Fernandez of orchestrating a cover-up in the investigation of Iran over the 1994 bombing of a Jewish community center was found dead in his apartment, authorities said on Monday.

Alberto Nisman, who had been delving into the blast at the AMIA Jewish community center in Buenos Aires that killed 85 people, said Wednesday that Fernandez opened secretive discussions with Iran and at least one of the men suspected of planting the bomb.

He said the scheme was intended to clear the suspects so that Argentina could start swapping grains for much-needed oil from Iran, which denies any connection with the bombing.

Mystery, accusations and international conspiracies surround the death of Argentine prosecutor Alberto Nisman, who was found dead with gunshot wounds to the head.

Reuters report that Nisman was found on Sunday night in his apartment ini the Puerto Madero neighbourhood with a handgun and a single bullet casing next to his body.

But was it suicide – and if so, why?

“Everything indicates it was a suicide,” National Security Secretary Sergio Berni told local television. “We have to see if gunpowder is found on his hands,” Reuters report.

Preliminary autopsy results from the morgue suggested “there was no third-person intervention in Nisman’s death,” the office of state prosecutor Viviana Fein said in a statement.

Fein told reporters she “could not rule out a provoked suicide” whereby someone forced or blackmailed Nisman to kill himself.

Nisman, who had seemed combative in recent interviews rather than frightened, had been due to take part in what promised to be a tough closed-door hearing in Congress on Monday to explain his accusations. Lawmakers allied with Fernandez said they were ready to grill Nisman about the charges.

On Monday those lawmakers told reporters they were shocked by the news and also suspected more than a straightforward suicide. “We want to know which mafiosi sector pushed the prosecutor to take this decision,” said Julian Dominguez, who leads the ruling coalition in the lower house of Congress.

The prosecutor’s security guards alerted his mother on Sunday afternoon that he was not answering his front door or phone. She found the door to his apartment locked from the inside and got a locksmith to open it. She found her son’s body on the floor of the bathroom and called the police.

Read more at Reuters