Arroyo Salgado's conviction that her former husband was murdered and her demand for new forensic tests could see her in open battle with the investigative prosecutor in the case, Viviana Fein, who yesterday announced the official test results: "The shot was fired at a distance of no more than 1cm, with the gun placed against the temple," Fein said, adding there was "no evidence of the participation of other persons".
A journalist credited with being the first to report Nisman's death has left Argentina because of fear for his safety. Damian Pachter of the Buenos Aires Herald left yesterday, the local journalism group Foro de Periodismo Argentino said. The group said Pachter reported on Saturday he was followed by unknown people and felt his safety was at risk.
Nisman's mysterious death, 24 hours before he was set to present explosive evidence against President Cristina Fernandez de Kirchner at an emergency congressional hearing, has electrified the nation and elevated the intrepid prosecutor to the status of a political martyr.
"I can't think about anything else," said a waitress at a corner cafe yesterday morning in the trendy Palermo Hollywood district, where patrons pored over magazines and newspapers, all with pictures of Nisman on their covers.
With enough twists and turns to satisfy the most avid conspiracy theorist, the case throws up probable culprits, ranging from the alleged Iranian terrorists whom he sought to bring to trial for the deaths of 85 victims at a Jewish community centre in Buenos Aires 20 years ago, to either Kirchner acolytes avenging his charges against the president or wrathful palace intriguers exacting revenge on the president by killing the man who dared to challenge her.
Last week Kirchner fingered spy chief "Jaime" Stiuso (whose real name is apparently Antonio Horacio Stiuso) as her main suspect. The 61-year-old intelligence operative has become a household name after Kirchner had alleged that Stiuso provided Nisman with hundreds of hours of intercepted calls on which the prosecutor built his case, accusing the president of attempting through secret negotiations to derail Nisman's attempts to extradite five Iranian officials to stand trial for the Amia Jewish community centre blast in 1994.
In return for immunity, Kirchner asked Iran for oil to plug the widening energy gap that is endangering Argentina's economy, Nisman alleged. Kirchner has denied the charge. "Everything is false," the president said about Nisman's charges.
Stiuso has never been seen in public and has been interviewed only once in his life, last month a few days before Kirchner fired him from his top post at the intelligence secretariat. "Stiuso was obsessed with the Amia case," says Rodis Recalt, the journalist from Noticias magazine who interviewed him. "He worked very closely with Nisman to build the case against Iran."
Why was Alberto Nisman investigating the attack?
He was handed the case on the 1994 bombing of a Jewish centre in Buenos Aires when the previous officials, including the presiding judge, were all dismissed for alleged corruption and cover-ups. The president at the time, Carlos Menem, is accused of perverting the investigation. They will go on trial this year.
What did he find?
In 2006 he officially stated that Iran was behind the bombing, which had long been suspected. But in recent years his investigation took on a twist, and he began to believe that Cristina Kirchner, the President, had cut a deal with Iran to clear it in return for oil deals.
Why would Iran attack Argentina?
At the time, the terrorist organisation Hizbollah - funded and armed by Iran - was carrying out a campaign of attacks on "soft" targets, as well as attacking American, French and Israeli military targets. Argentina has Latin America's largest Jewish population, and the building of the Argentine Israelite Mutual Association was the focus of their community. Argentina had also just cancelled plans to co-operate with Iran on nuclear technology.
Why would Kirchner want to cut a deal with Iran?
Nisman said she wanted to ensure favourable deals for oil, in return for Argentina selling grains to Iran. Kirchner has said that grain deals are not done by the state, but rather by large companies such as Cargill. And she says that Argentina never bought oil from Iran. Is this because the deal didn't go through?
Who wanted him dead?
At first glance, the Government of Argentina would appear to want to silence him. But his accusations against Kirchner had already been made, and his death looks bad for the Government. Furthermore, Kirchner has said that wiretaps of conversations between Iranian and Argentine spies and intermediaries alluding to a deal with Iran were fake.
Iran was fingered by Nisman as being behind the bombing. He claimed that a lot of senior people, who remain in the inner circle of power, orchestrated the plot. Some suggest that his work was ruining Iran 's campaign to shed its pariah status. He has been making accusations against Iran since 2006.
Iranian state news agencies say that Israel was behind his death, and Mossad carried it out to make it look like Iran killed him.
Some believe he was working with the CIA to discredit either Kirchner or Iran. WikiLeaks cables show he had contact with American Embassy officials, but Nisman brushed off those accusations, saying that he spoke to lots of people.
What happens now?
An investigation has been opened into Nisman's death. His inquiry has been taken over by Alberto Gentilli, who was working with him. A third case relating to corruption during the first decade of inquiry will be heard this year.
- Observer, AP, Daily Telegraph