The assistant who supplied late Argentine prosecutor Alberto Nisman with the gun used in his mysterious death was fired on Monday, officials said, according to AFP.
The justice ministry announced the dismissal of Diego Lagomarsino, a computer expert at the Argentine public prosecutor's office and the last person known to have seen Nisman alive.
Lagomarsino was fired because Nisman's interim replacement "reported that he did no work," Luis Villanueva, a spokesman for the public prosecutor's office, told radio station Nacional Rock.
Nisman was found dead in his apartment with a gunshot wound to the head on January 18, on the eve of a Congressional hearing at which he was expected to accuse President Cristina Kirchner of covering up high-ranking Iranian officials' role in a deadly 1994 bombing at a Buenos Aires Jewish center.
Lagomarsino has admitted to lending Nisman the .22-caliber revolver that killed him, though it remains a mystery who pulled the trigger. He had already been under suspension when the decision to sack him was made.
Since the death, initially labeled a suicide, suspicion has fallen on Kirchner's government of orchestrating Nisman's murder. The president for her part has suggested Nisman was manipulated by disgruntled former intelligence agents who then killed him to smear her.
Lagomarsino, who has been charged with giving a firearm to someone other than its registered owner, says he brought Nisman the gun because the late prosecutor told him he feared for his life and no longer trusted even his bodyguards.
The government has said Lagomarsino is an agent of Antonio "Jaime" Stiuso, a powerful ex-spy who Kirchner says was feeding information to Nisman.
The prosecutor investigating Nisman's death, Viviana Fein, said Stiuso will give a deposition this week after failing to respond to a summons last week.
"I need to see what relationship he had with Mr Nisman," Fein said.
She said Stiuso had received "repeated" phone calls from Nisman the night he died.
Fein also said a second test for gunpowder residue had been ordered after initial forensic testing found no trace of gunpowder on Nisman's hands.
"My greatest wish is to discover the truth. Not just for me but for all Argentine citizens, so we know what was behind this, if there was a motive, if it was induced, if it was (Nisman's) own decision or if there was a third person who fired the shot," she told Radio La Red.
Kirchner has announced plans to disband Argentina's Intelligence Office and replace it with a new federal intelligence agency following the Nisman incident.
The bombing at the Argentine Jewish Mutual Association killed 85 people and wounded 300.
Nisman had accused Iran of ordering the attack via Hezbollah, and alleged that Kirchner and Foreign Minister Hector Timerman were trying to shield Iranian officials from prosecution in exchange for oil. It was revealed that he had drafted arrest warrants for both before he was found dead.
AFP contributed to this report.