There was no sign of intervention by others in the shooting death of Alberto Nisman, the special prosecutor in the AMIA Jewish Centre bombing, according to preliminary autopsy reports.

“There was no intervention from third parties in the death,” Buenos Aires Prosecutor Viviana Fein said Monday afternoon in a statement, citing the report given to her by the head of the judicial morgue, the Argentine media reported.

Fein also said in the statement that she would wait until the final results of Nisman’s autopsy, as well as other forensic tests, in order to rule out other possible causes of death.

Nisman, 51, was found dead on Monday morning in the bathroom of his Buenos Aires apartment with a gunshot wound from a .22-caliber pistol.

“All signs point to suicide,” Argentine Security Secretary Sergio Berni said prior to the preliminary autopsy reports, according to the French news agency AFP.

Nisman’s body was discovered 12 hours before a closed-door meeting with congressional lawmakers in which he was expected to reveal details of his allegations against President Cristina Fernandez de Kirchner and Foreign Minister Hector Timerman for their alleged cover up of Iran’s role in the AMIA bombing, which killed 85 and injured hundreds.

According to Nisman’s accusations, contained in a lawsuit filed last week in federal court, Fernandez covered up for former Iranian officials accused of involvement in the attack. Timerman, who is Jewish, also was named in the lawsuit, which seeks a freeze on Kirchner’s assets.

In a statement expressing its condolences, the Simon Wiesenthal Center demanded an independent investigation into the circumstances of Nisman’s death and said “his denunciation regarding an alleged cover-up by the Argentine government must be investigated till the end.”

Abraham Foxman, the national director the Anti-Defamation League, in a statement called Nisman “a courageous and principled seeker of truth and justice who cared deeply for the victims of the AMIA bombing and their families and pursued his investigation wherever the facts took him.”

B’nai B’rith International said his death “creates a gaping void in the pursuit of terrorists.”