Italian President Sergio Mattarella has said he is expecting "full" cooperation from Egypt on the fifth anniversary of the disappearance of student Giulio Regeni.
Last Wednesday, Rome's Public Prosecutor's Office formally requested the opening of a trial against four Egyptian police officers implicated in the murder.
Regeni, 28, was abducted by assailants in Cairo in January 2016, and his mutilated body was found several days later in the city's suburbs. The Cambridge University doctoral student had been researching Egyptian trade unions, a very sensitive subject in the country.
Four men, including a general and major within Egypt's National Security Agency, are suspected of kidnapping, grievous bodily harm, and conspiracy to commit murder, Rome has stated.
"We expect a full and adequate response from the Egyptian authorities, who have been relentlessly urged to do so by our diplomacy," said Mattarella on Monday.
"On this painful anniversary, I reiterate my wish for a common and convergent commitment to find the truth and bring to justice those guilty of a crime that has rightly attracted the attention and solidarity of the European Union.
"This is a responsible commitment, unanimously expected by the families, the institutions of the Republic, and the entire European public opinion".
Italian investigators have accused the Egyptian officers of torturing Regeni for days by "burning, kicking, punching, using knives and sticks" before killing him.
Egypt has strongly denied the allegations and said it believes that Regeni was the victim of a robbery.
"The action of the Public Prosecutor's Office of Rome, amidst many difficulties, has led to the conclusion of investigations that have identified a framework of serious responsibilities, which, soon, will be submitted to the scrutiny of a trial, for the consequent sanctions to the guilty," wrote President Mattarella.
If the trial requested by Rome is allowed to proceed, the four Egyptian suspects are unlikely to be extradited and court proceedings will take place in their absence.
Last month, the Italian government said it was "unacceptable" that the Egyptian public prosecutor's office had decided to release the four men from detention. Investigations against a fifth suspected officer were dropped last month, Italian prosecutors said.
"The Rome prosecutor's office has stuck firm to the commitment to do everything to ascertain every responsibility,'' Public Prosecutor Michele Prestipino told a parliamentary commission.
"We owed it to the memory of Giulio Regeni and to being magistrates of this Republic."
The case has strained relations between Italy and Egypt, as Rome has repeatedly accused Cairo's authorities of failing to cooperate. In 2016, Italy withdrew its ambassador to protest against perceived reluctance by Egypt to investigate properly.
Last week, activists from Human Rights Watch wrote to EU member states to express their "serious concerns" about human rights violations in Egypt.
The letter, written ahead of the EU's Foreign Affairs Council discussion on Egypt, explicitly referred to Cairo's "continued efforts to hinder investigations into the abduction, torture, and killing of Giulio Regeni".
On Monday, Amnesty Italy encouraged other social media users to post messages of support for Giulio Regeni on a yellow background under the hashtag #VeritaegiustiziaperGiulioRegeni (#TruthAndJusticeForGiulioRegeni).
"A heartfelt thanks to the Italian judiciary for the important work done," tweeted European Parliament President David Sassoli.
"We will never tire of asking for justice."