Egypt authorities in new face-saving concession over Regeni's murder

The CCTV footage comes from security cameras at a central Cairo metro station believed to have recorded the last images of the Italian student before his disappearance.

Cairo also approved a request to send experts from "the only German company specialised in retrieving data from the camera recording device" at that metro station, a prosecution statement said.

Egypt said the software needed to recover the deleted footage was expensive, and had asked Italy to help.

The 28-year-old Cambridge University PhD student had gone missing on 25 January last year in central Cairo, as police were out in force in anticipation of protests commemorating the fifth anniversary of the popular uprising that toppled former president Hosni Mubarak.

His mutilated body was found a week later at the side of a road on Cairo's outskirts, suggesting he died of torture at the hands of security services during an interrogation, an allegation the Egyptian government has strongly denied.

He had been researching street vendor trade unions, an especially sensitive political issue in Egypt, with successive governments fearing strikes and unrest.

Egypt has forcefully denied that its police were involved in his abduction, suggesting several alternative scenarios, including that Regeni had been killed in a road accident.

In December, prosecutors said they had questioned officers who killed members of a criminal gang in March and claimed to have found Regeni's belongings, including his passport, in the home of the gang leader's wife.

That account met with suspicion in Italy, where politicians and the media have suggested that Egyptian police were behind the student's death.

Egypt later debunked its own story, saying the gang may not have had any links to Regeni's death, but it never explained why the student's ID cards were found at the scene, again prompting speculation of a police cover-up.

Regeni's killing has poisoned Egypt's close relations with Italy. In April, Rome recalled its ambassador to Cairo for consultations to protest what it said was the slow pace of the investigation and the perceived lack of cooperation.