The death of Argentine federal prosecutor Alberto Nisman exactly a year ago today, remains bogged down in intrigue and unanswered questions. The difference, however, is that the recent change in government has given the case new momentum.

At the time he was found shot in the head in his bathroom, Nisman was investigating the 1994 bombing of the AMIA jewish center in Buenos Aires that killed 85 people.

Four days before his death Nisman had accused then President Cristina Fernández de Kirchner of covering up Iran's involvement in the bombing. He had been due to present his findings to Congress the day after.

Nisman's investigation had already divided Argentina, and his family immediately alleged he was murdered. The former government initially claimed he had committed suicide, before saying it was part of a plot to destabilize the president.

"I have the best expectations for the case," Manuel Romero Victorica, lawyer of Nisman's daughters, told VICE News about the renewed push to clarify how the prosecutor really died.

President Mauricio Macri marked the anniversary of Nisman's death by meeting the prosecutor's daughters and promising them to "do justice in his memory."

Earlier this month Macri, who was inaugurated in December after beating President Fernández's chosen candidate in elections, also ordered the declassification of the documents from multiple government agencies related to the investigation that Nisman was carrying out when he died.

The president instructed the agencies to submit all the documentation to judge Fabiana Palmaghini who took charge of the investigation of Nisman's death from December 17 on the grounds that it had been "paralyzed" during the previous 11 months.

Up until then the case had been in the hands of a prosecutor called Viviana Fein who critics say never wanted the case to move forward.

Four months after Nisman was found dead, a television show aired footage showing forensic experts taking fingerprints without gloves, cleaning the blood off the gun that killed Nisman with toilet paper, and leaving traces of hair and saliva uncollected.

There were no traces of gunpowder on his hands and his phone was deleted. A forensic analysis of the cell phone determined it had a virus.

Fein had rejected any suggestion that the evidence had been contaminated or the investigation inadequate, and called the work of the forensic team "brilliant."

Nisman´s controversial investigation led him to claim that President Fernández de Kirchner was trying to help Iran cover up its involvement in the 1994 bombing. He said she had sought to help get Interpol warrants against five Iranians lifted.

Nisman wanted to oblige the president and other members of her government to answer questions in the case in which he said they had sought to "manufacture the innocence of Iran" in exchange for trade deals involving grains and oil.

"I am calm, I am not a makeshift. I know I'm accusing President Cristina Kirchner, and that's no small matter. I already spoke, now it's time to let the evidence talk, " Nisman told VICE News two days before he died, in the last interview he gave to any international media outlet.

Watch the VICE News documentary_,_ **Who Killed Alberto Nisman? - In Search of Truth in Argentina:**

Jorge Capitanich, the then chief of staff of Cristina Kirchner, described the investigation as "absurd, illogical, irrational, ludicrous. It violates basic articles of the Constitution."

Others accused the prosecutor of being part of a destabilization plan orchestrated by the United States.

At the same time photographs of the prosecutor's private life at parties and trips circulated and the government denounced his mother for money laundering.

A month after he died, federal judge Daniel Rafecas threw out Nisman's investigation alleging then President Fernández had helped cover up for Iran in the AMIA bombing.

After languishing through the final months of the Fernández de Kirchner presidency, the many questions, accusations and counter accusations still swirling around Nisman's work and death are now once again at the forefront of the national debate.

"The obvious attempts made throughout the year by tarnishing his image aiming to distract attention from the only important thing, which is to determine how he died," the Association of Prosecutors said. "Nisman, not only was in charge of investigating the worst terrorist attack on our country, but also a serious investigation involving, among others the former president."

The last person known to have seen Alberto Nisman alive was Diego Lagomarsino, a computer technician who worked alongside him in his office.

Lagomarsino has accepted that he gave Nisman the gun with which he was killed, but has denied that he had anything to do with his death.

"Alberto called me on the Saturday, asked me for a gun, I gave it to him, and after that he died by that weapon," he told reporters on Monday. "But the truth is I don't know what happened. If he committed suicide, we need to know if he did it because he wanted to, or if somebody forced him to."