An Argentinian judge has dismissed the case against President Cristina Fernández de Kirchner for allegedly shielding Iranian officials from prosecution over the 1994 bombing of a Buenos Aires Jewish centre.

Prosecutors had sought to relaunch the case against Fernández that was being brought by their late colleague Alberto Nisman, who died mysteriously last month after accusing Fernández of protecting Iranians suspected of ordering the deadly bombing at the Argentinian Jewish Mutual Association.

But Judge Daniel Rafecas said on Thursday that documents originally filed by Nisman failed to meet standards needed to open a formal court investigation.

“I dismiss the case because no crime was committed,” Rafecas said.

Nisman was found with a fatal gunshot wound to the head in his bathroom on 18 January, four days after filing a report accusing Iran of ordering the attack via the Lebanese militant group Hezbollah, and alleging that Fernández was trying to shield Iranian officials from prosecution in exchange for oil.

Since his death, initially labelled a suicide, suspicion has fallen on Fernández’s government of orchestrating Nisman’s murder.

The president has suggested the prosecutor was manipulated by disgruntled former intelligence agents who then killed him to smear her.

Earlier on Thursday, Argentinian MPs passed a bill to reform the country’s intelligence service, which Fernández has suggested has strayed out of civilian control .

Fernández says the new state security body established under the legislation will be more accountable. But opponents say the legislation does little more than change the name of the spy agency and has been rushed through Congress. The opposition boycotted some of the debate.

The chamber of deputies approved the bill by a majority of 131 to 71 after an overnight debate. Fernández now has to sign the bill, which she is expected to do in the coming days.

The long-unsolved bombing at the Argentinian Jewish Mutual Association killed 85 people and wounded 300.