BUENOS AIRES — Alberto Nisman, the prosecutor whose mysterious death has gripped Argentina, had drafted a request for the arrest of President Cristina Fernández de Kirchner, accusing her of trying to shield Iranian officials from responsibility in the 1994 bombing of a Jewish center here, the lead investigator into his death said Tuesday.

The 26-page document, which was found in the garbage at Mr. Nisman’s apartment, also sought the arrest of Héctor Timerman, Argentina’s foreign minister. Both Mrs. Kirchner and Mr. Timerman have repeatedly denied Mr. Nisman’s accusation that they tried to reach a secret deal with Iran to lift international arrest warrants for Iranian officials wanted in connection with the bombing.

The new revelation that Mr. Nisman had drafted documents seeking the arrest of the president and the foreign minister illustrates the heightened tensions between the prosecutor and the government before he was found dead on Jan. 18 at his apartment with a gunshot wound to his head. He had been scheduled the next day to provide details before Congress about his accusations against Mrs. Kirchner.

“It would have provoked a crisis without precedents in Argentina,” said Sergio Berensztein, a political analyst, about the impact of the arrest requests if they had been issued. He noted that previous legal cases had shaken Argentina’s political establishment, but he emphasized that this case involved a request to arrest a sitting president.