Cairo (AFP) - Egypt's prosecution said Wednesday it has handed over to Italian investigators documents requested by Rome to help the probe into the kidnapping and murder last year of an Italian student.

Giulio Regeni, a 28-year-old Cambridge University PhD student, disappeared in central Cairo in January last year and his body, bearing signs of torture, was later found by the side of a road.

"The Egyptian investigators gave their Italian counterparts the first bunch of documents requested by the Rome prosecution," said a joint statement released by the Egyptian and Italian prosecutions.

It was released as a team of Italian investigators wound up a visit to Cairo.

Egypt had previously dismissed as "unconstitutional" a request by Italy to retrieve thousands of phone records from the areas where Regeni lived, disappeared and where his body was found.

Wednesday's statement also said a deal would be signed later this month aimed at retrieving footage from CCTV cameras from a Cairo metro station Regeni is believed to have entered before being abducted.

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

Regeni's case badly strained the traditionally close relations between Rome and Cairo.

The slow pace of the investigation prompted Italy to withdraw its ambassador from Cairo.

Egyptian police initially suggested Regeni died in a traffic accident, but later said he was killed by an anti-foreigner criminal gang whose members were all killed in a shootout with police.

That account was met with suspicion in Italy, where politicians and the media have suggested Regeni was slain by elements of Egypt's security services.

An Italian autopsy showed that Regeni's body was covered with cuts and his bones were broken, indicating he had been hit with "fists, batons and hammers".

A letter "X" was carved on his forehead and hand, according to the report cited by Italian media.

Regeni was in Cairo researching Egyptian street vendor trade unions, a sensitive topic, and had written articles critical of the government under a pen name.

He disappeared from central Cairo on January 25, 2016, a day when security in the capital was tight as it was the fifth anniversary of the uprising that ousted longtime leader Hosni Mubarak.