Three Egyptian security officials have been convicted by a Rome court over the kidnapping of an Italian student whose tortured body was found in Cairo a decade ago.

The men, who were tried in absentia, denied the charges. On Monday they were sentenced to 10 years in prison on charges of aggravated kidnapping. A fourth Egyptian defendant was acquitted.

Giulio Regeni, 28, was studying for a doctorate at Cambridge University when he went missing while on a research trip in Egypt in 2016.

Days later, his mutilated body was found in a ditch near Cairo. An autopsy later revealed he had been tortured.

Italian and Egyptian prosecutors originally investigated the case together, but reached opposing conclusions.

Egyptian authorities argued criminal gangsters were to blame for Regeni's murder and suggested various other explanations for his death, including a car accident, failed drug deal, or botched robbery.

They also denied any state involvement in Regeni's disappearance or death.

But prosecutors in Rome concluded that the Egyptian national security agency was involved in the crime.

The four defendants were Gen Tariq Sabir, Col Usham Helmi, Col Athar Kamel Mohamed Ibrahim and Maj Magdi Ibrahim Abdelal Sharif. Sabir was acquitted.

Rome's chief prosecutor and a lawyer for Regeni's family welcomed the verdict.

"From today, people around the world can feel safer," Alessandra Ballerini, the family's lawyer, said. "Impunity can be defeated and democracies can place limits on arbitrary power."

Regeni's family have campaigned throughout the decade for justice. As the verdict was read out, there was silence from family members and supporters in court who wore yellow t-shirts and badges, the colour of their campaign, AFP reported.