ROME, 8 Dec. (Reuters) - Egyptian prosecutors investigating the murder of student Giulio Regeni gave their Italian counterparts a pile of new documents on Wednesday, but there has been no breakthrough in the case, a judicial source said.

"Frankly we hoped for something more," said the Italy-based source with direct knowledge of the case, who declined to be named because he was not authorized to speak to the media.

Regeni, who was doing postgraduate research into Egyptian trade unions, was last seen by friends on Jan. 25. His body, showing signs of extensive torture, was found in a ditch on the outskirts of Cairo on Feb. 3.

Egypt has rejected suggestions from human rights groups that Egyptian security services appeared responsible for the 28-year-old's death. Italy has constantly complained about the slow progress in the investigation and in April withdrew its ambassador in Cairo in protest.

In the latest of several meetings, Egyptian Public Prosecutor Nabil Sadek came to Rome on Tuesday for two days of talks with Italian prosecutors and handed over "all the documents" requested by Italy in September, a statement by the two sides said.

Sadek also met Regeni's parents to pass on condolences.

In a speech to his Democratic Party, outgoing Italian Prime Minister Matteo Renzi suggested the investigation was progressing. "I believe that an important step forward has been made," he said, without giving details.

The judicial source said he did not know what Renzi might be referring to. "We have not reached a turning point, but we are carrying on," he told Reuters. "...If we continue with these meetings we will very slowly get towards the truth."

Among documents handed over was the transcript of testimony given by the head of the Cairo street sellers' union, who "spontaneously told police of the contacts he had with Giulio Regeni" until three days before the Cambridge student vanished.

Egypt has said its police carried out checks on Regeni's activities following the concerns raised by the union chief, but found nothing of interest.

Human rights groups have said torture marks indicated Regeni died at the hands of the security forces, an allegation Cairo denies.

But security and intelligence sources told Reuters in April that Regeni had been arrested outside a Cairo metro station on Jan. 25 and was taken to a Homeland Security compound.

The judicial source said Italy would make an official request for further documentation from Cairo later this month.