Italian investigators looking into the death of student Giulio Regeni in Egypt had requested the call logs of thousands of phone numbers, a senior Egyptian prosecutor said on Saturday, describing the request as “illegal and unconstitutional.”

An Egyptian team headed to Rome this week to meet with Italian officials looking into the killing of Regeni, whose body was found in Cairo in February bearing signs of torture.

On Friday, Italy recalled its ambassador to Egypt for "consultations."

The request for phone records was the main point of contention between the Italian and Egyptians during the Rome meetings, said Mostafa Soliman, an aide to the prosecutor-general and the head of the Egyptian delegation.

"The Italian authorities wanted access to the call log of a huge number of citizens, which could reach a million, who were around student Gulio Regeni's house and the area where the police found his body," Soliman said at a press conference in Cairo.

"Although Italy said that this request would make both countries issue unified statements concerning the investigations process, Egypt had rejected it as it violates the Egyptian constitution and the law regulating communications," he added.

Soliman said that the Egyptian constitution bans tracking any forms of communication used by ordinary people, as long as they are not charged or implicated in any criminal cases or ongoing investigations.

"We can't track the call logs of innocent people," he said.

The Egyptian delegation which flew to Rome on Wednesday submitted a 2,000-page report to Italy's chief prosecutor Giuseppe Pignatone on its findings in the killing of Regeni.

However, Soliman said that the talks between the two sides were "friendly" and the Italian authorities did not ask them about names and information being circulated by the media related to Regeni's murder.

"When we asked the Italian authorities whether they need certain names to be added to the investigations or not, the Italian top prosecutor said that there are no names as all of them are media claims," he said.

Discussing the security cameras around Behooth metro station, Regeni's last-known location before he went missing on 25 January, Soliman said that the footage was not available as the cameras were not able to save videos.

"We contacted the American company which produced the cameras and it told us that there are no saving options in their cameras, but they informed us that there is German software available which can retrieve old videos with a 50 percent chance of success," he said. 

"But it's very expensive, so we contacted the Italian authorities to help us with getting it," he added.

Regeni, a 28-year-old PhD student, vanished from the streets of Cairo on 25 January. His body was discovered in a ditch on the outskirts of the city nine days later, showing signs of extensive torture.

Last month, Egyptian police said they had found Regeni's passport and other belongings in the possession of one of the families of a member of an alleged gang of kidnappers who robbed foreigners.

Police killed all four alleged robbers in a shootout in late March.

Italian officials responded to the accounts of the link with Regeni with public scepticism.