BUENOS AIRES (AFP) - Argentine prosecutor Alberto Nisman drafted an arrest warrant for President Cristina Kirchner that was recovered from the trash at the investigator's apartment following his mysterious death last month, officials said on Tuesday.

Prosecutor Viviana Fein - who on Monday had denied the existence of the document - admitted the 26-page warrant for Ms Kirchner's arrest, dated June 14, 2014, was discovered after Mr Nisman's death from a gunshot wound on Jan 18.

Mr Nisman, 51, died on the eve of an appearance before Argentine lawmakers in which he was expected to accuse Ms Kirchner of mounting a cover-up over the 1994 bombing of a Jewish centre that left 85 people dead and 300 wounded. It was the worst terror strike on Argentina's soil in its modern history.

Tuesday's revelation that Mr Nisman had considered seeking the arrest of Ms Kirchner provided a fresh twist to a scandal, which has captivated Argentina since the prosecutor's death at his home in Buenos Aires.

News of a possible arrest warrant being discovered was first reported by the Clarin newspaper on Sunday.

Existence of the draft warrant was swiftly denied by Ms Fein, who is investigating Mr Nisman's death, and Cabinet chief Jorge Capitanich, who branded the report "rubbish" before theatrically tearing up a copy of the Clarin story before television camera crews.

However, Ms Fein was forced into an embarrassing U-turn on Tuesday, admitting that she had made an "honest mistake" by denying the warrant existed.

"There was a misunderstanding, an unintentional mistake. There was no misconduct," Ms Fein said, denying that her investigation faced external pressure from "the government or anyone".

The revelation added another layer of intrigue to a story that seems certain to deepen the cynicism of Argentines towards their rulers and institutions of power.

In a criminal probe released four days before his death, Mr Nisman alleged Ms Kirchner and other officials had struck a deal with Iran aimed at shielding Teheran officials linked to the 1994 bombing in exchange for lucrative trade agreements.

According to polls, some 70 per cent of the population believe they will never know the truth behind Mr Nisman's death.

Mr Nisman's demise, which was initially believed to have been suicide, is being investigated as a "suspicious death".

Argentines are divided over whether Mr Nisman was murdered by the government or whether he was killed as a part of a plot to smear Ms Kirchner, as the President herself has claimed.