Giulio Regeni, a Cambridge University PhD student who was researching Egyptian labour movements, disappeared on January 25th and his badly mutilated body was found a week later.
Egypt's attorney general Nabil Sadeq discussed the investigation with Pignatone, who was visiting Cairo along with his deputy Sergio Colaiocco after an invitation.
"The Italian side proposed its assistance to Egyptian investigators and to provide all information in its possession," said a statement, stressing the determination of both parties to shed light on the case.
Last Thursday, the European Parliament called on Egypt to cooperate in the probe, saying it came within the context of deaths in custody in the North African country.
In February, Egyptian Interior Minister Magdy Abdel Ghaffar rejected charges of security forces being involved in the murder of Regeni.
The 28-year-old's slaying became a cause celebre among academics around the world and has turned the spotlight on what rights and opposition groups say are increasing abuses by security services under the military-backed government in Cairo.
Police and intelligence services in Egypt are frequently accused of carrying out torture in arbitrary detention or the killing of detainees.