A crusading Argentine judge has ordered the arrest of the country’s former president Cristina Fernandez de Kirchner on charges of “treason against the fatherland,” accusing her of covering up Iranian involvement in the country’s worst-ever terrorist attack.

The 1994 bombing of a Buenos Aires Jewish cultural centre, AMIA, killed 85 people. No one has ever been successfully prosecuted for the crime.

An Argentine prosecutor, Alberto Nisman, was investigating. On January 14, 2015, he filed a criminal claim accusing Mrs Kirchner and others of secretly negotiating a deal with Tehran to offer immunity for Iranian suspects in the bombing, in exchange for Iranian oil.

Mrs Kirchner said the allegations were part of a broad international conspiracy to undermine her presidency. Her government said it had been in talks with Iran to create a commission aimed at clarifying who was responsible for the bombing.

Mr Nisman was due to present his findings before Congress on January 20, but the day before was found dead inside his apartment, with a bullet fired into his head.

Mrs Kirchner initially said it was suicide, but then said she believed it was a murder orchestrated to smear her. Last month an Argentine panel concluded that he had been murdered.