An official investigating the January 2015 death of Argentinian prosecutor Alberto Nisman has said that he was probably murdered.

Mr Nisman was found dead in the bathroom of his Buenos Aires apartment, just days after accusing then-president Cristina Fernández de Kirchner of covering up Iran's alleged role in the 1994 bombing of the Amia Jewish centre in Buenos Aires in return for trade benefits with Tehran.

Mr Nisan's death was officially classified as a suicide, which his family and friends dismissed as absurd.

He was discovered with a pistol by his side and a bullet in his head hours before he was due to appear in the Argentinian Congress to present what he claimed was proof of his accusations against Ms Fernández.

"The evidence up to this point supports the hypothesis that Alberto Nisman was the victim of the crime of homicide," wrote Ricardo Sáenz, district attorney for the Buenos Aires Criminal Appeals Court, last week. He recommended that the case be handed over to federal authorities and pursued as a murder investigation. He added that Mr Nisman - who was leading the investigation into the Amia attack - had received a number of death threats.

Argentina's new President, Mauricio Macri, promised justice when he met Mr Nisman's daughters last month.