BUENOS AIRES Ė Police raided the house of Diego Lagomarsino, whose gun was used to kill prosecutor Alberto Nisman.
Lagomarsino, an IT specialist who worked with Nisman, admitted providing the gun that was found with the victim and was charged for it.
He alleges he gave his gun to the prosecutor, who had grave concerns about his own security.
A search warrant was issued by Judge Fabiana Palmaghini before Metropolitan Police raided Lagomarsinoís house on Monday in Martinez, on the outskirts of Buenos Aires, local media reported.
Nisman, the special prosecutor investigating the 1994 bomb attack on the Argentine Israelite Mutual Association, or AMIA, building in Buenos Aires, was found dead in his Buenos Aires apartment on Jan. 18.
News of his death followed just four days after he filed a complaint against Argentine President Cristina Fernandez for alleged involvement in covering up Iranís involvement in the attack.
Lagomarsino has admitted he went to Nismanís apartment on Saturday, Jan. 17.
According to forensic investigators hired by Nismanís ex-wife Sandra Arroyo Salgado, Nismanís death qualifies as a murder Ė not accident or suicide Ė, and he may have died as early as Jan. 17.
However, Lagomarsinoís defense lawyer Maximiliano Rusconi claims that evidence shows the prosecutor was alive and using his laptop on Sunday morning.
Rusconi told media that preliminary investigations confirmed a local connection was made from Nismanís computer, contradicting Salgadoís claim.