The family of Italian student Giulio Regeni, who was found murdered in Egypt in February, demanded on Tuesday at a press conference that the Italian senate show a tough response "if Egypt fails to uncover the truth" behind the murder.

Giulio's mother, Paola Regeni, said she may release a photograph of her son's body to show the world what happened to him in Egypt if his murderers are not found.

Regeni's body was found on 3 February with signs of torture on a roadside on the outskirts of Cairo.

"I only recognised him because of the tip of his nose. As for everything else, it was no longer him," she said in the first news conference the family gave since Giulio's body was found.

Regeni, a 28-year-old political science PhD student, disappeared on 25 January, the five-year anniversary of the 2011 revolution, after leaving his home in Dokki, an upper-middle class area in Cairo, to meet a friend downtown.

Human rights groups have said the signs of torture suggest he was killed by Egyptian security forces, an allegation Cairo has vigorously denied.

Egyptian officials are due in Italy on 5 April to discuss the investigation.

"If 5 April proves to be a wash-out, we expect a strong response from our government, a really strong one," Paola Regeni said.

The family's lawyer, Alessandra Ballerini, said the Italian autopsy showed that Regeni was alive until 1 or 2 February, and that there was no ransom bid or money taken from his bank account in the days after his disappearance.

"Whatever the truth, it is clearly very uncomfortable for the [Egyptian] regime," she said.

The head of the Italian parliament's human rights committee, Luigi Manconi, who also took part in the news conference, said the government should recall Italy's ambassador to Cairo and declare Egypt unsafe for visitors if the investigation went nowhere.

"Relations should not be broken, but they should face a particularly significant revision," said Manconi, a member of Prime Minister Matteo Renzi's Democratic Party.

Giulio Regeni's father, Claudio, said he supported this call.

Last week, Egyptian police said they had discovered Regeni's identity documents in the possession of a criminal gang whose alleged members were killed in a shootout with police.

Both Italian officials and Regeni's family dismissed the possibility that the gang was involved in the murder.

Egyptian officials have not confirmed nor ruled out the possibility.

On Sunday, Italy's interior minister Angelino Alfano announced that Egyptian investigators agreed to extend the investigation after pressure from Rome.