Prosecutors in Rome say Giulio Regeni, a 28-year-old Cambridge University graduate, was abducted and tortured to death after leaving his apartment in the Dokki neighbourhood of Cairo on 25 January 2016 to meet a friend in the city centre.
Regeni never arrived at his friend's apartment and his body was not found until 3 February 2016.
The Italian had been researching trade union activities in Egypt for a PhD and prosecutors believe this antagonised powerful elements in the Egyptian police.
Regeni disappeared on the fifth anniversary of the start of the uprising which ended the rule of Hosni Mubarak, who had been Egypt’s president for 30 years.
On Thursday, 14 October, Egypt’s former head of state security, Major General Tarek Sabir, will go on trial for “aggravated kidnapping” along with Major Magdi Sharif, from Egypt's General Intelligence, and two police colonels, Hisham Helmy and Ather Kamal.
Sharif has also been accused of "conspiracy to commit aggravated murder."
Prime Minister Mario Draghi's office said the Italian government, which considers itself a wronged party, would be a civil plaintiff in the trial.
Last month Italy’s Foreign Minister Luigi Di Maio told a parliamentary commission of inquiry: "The search for the truth has always been, and will continue to be, a fundamental goal in our relations with Egypt.”
“Achieving a definitive picture, in the framework of a fair trial, will not bring Giulio back to his parents, but it will reaffirm the strength of justice, transparency and the rule of law in which he believed,” added Di Maio.
The suspects have never commented on the allegations but Egypt has always denied Regeni was killed by its security services.
The Egyptian police killed four men in a shootout in March 2016 and claimed they were a gang of criminals who had been responsible for kidnapping and robbing Regeni.
But the Italian authorities were always doubtful of that explanation and their suspicions grew when the body was brought back to Italy and a pathologist found Regeni had suffered extensive bruising as a result of being kicked, punched and beaten with a stick.
Seven of his ribs were broken, as well as all his fingers and toes and he had also been tortured on the soles of his feet and burned with cigarettes.
The cause of death was given as a brain haemorrhage and a broken spine.
Italian investigators found mobile phone records which showed the gang's leader, Tarek Abdel Fattah, was 60 miles from Cairo on the day he supposedly kidnapped Regeni.
Several witnesses also claimed the four Egyptians had been executed in cold blood by the police, rather than being killed in a shootout.
The Italian government said it would seek to extradite anyone convicted by the Rome court, which is likely to lead to another diplomatic crisis with Egypt, whose President Abdel Fattah el-Sisi is a former director of military intelligence who draws much of his support from the policy and army.