Italy's chief prosecutor has arrived in Egypt to follow up on the investigation into the killing of an Italian researcher whose body was found on the outskirts of Cairo bearing signs of torture.

Suspicions that Egypt's security forces may have been involved in the killing of Giulio Regeni, 28, have raised tensions between Cairo and Europe.

The European Parliament recently adopted a resolution expressing "grave concern" that Egyptian authorities were behind the killing of Regeni, who went missing on Jan. 25, the fifth anniversary of the 2011 uprising, when police were heavily deployed across Cairo.

The chief prosecutor, Giuseppe Pignatone, arrived Monday. Earlier this month Italian officials said Egypt has not fully cooperated with requests for information.