Argentine President Cristina Fernandez de Kirchner has been formally accused of trying to cover up Iranian involvement in a deadly bombing.
The allegations were first aired by prosecutor Alberto Nisman, before he was found dead from a gunshot wound last month.
His death - which roused suspicion despite being labelled suicide - came a day before he was due to give evidence to Congress over the Argentine Jewish Mutual Association bombing, which killed 85.
Mr Nisman claimed the President protected Iranian officials from prosecution over the 1994 bombing in exchange for oil.
Federal Prosecutor Gerardo Pollicita has now decided to go ahead with the probe.
"An investigation will be initiated with an eye toward substantiating ... the accusations and whether those responsible can be held criminally responsible," he said.
Three prosecutors and a coordinator have been named to take over the case.
They have already endorsed Mr Nisman's conclusions, accusing Mrs Kirchner, Foreign Minister Hector Timerman and others of a cover-up.
A judge will now decide whether to call Mrs Kirchner to make a statement.
The 61-year-old has presidential immunity which can only be removed with a two-thirds majority in Congress.
Mrs Kirchner's cabinet chief, Jorge Capitanich, has accused the courts of trying to stage a "judicial coup" against the embattled leader.
The government says "no action on the part of government officials was designed to dis-incriminate Iranian citizens".
The bombing at the Buenos Aires Jewish center, known as AMIA, was the deadliest such attack in Argentina's history.
An initial investigation ended with no convictions.
In 2006 Mr Nisman was named to reopen the case.
He accused Iran of ordering the attack via Hezbollah and requested arrest warrants for five officials.
Four days before he was found dead he filed a report accusing Mrs Kirchner and Mr Timerman of colluding to shield the Iranians.
