Giulio Regeni
Cambridge student Giulio Regeni, who was from Italy, was found dead in CairoTwitter

A University of Cambridge student found dead in Cairo was freelancing for a left-wing Italian newspaper using a pseudonym, as he feared his work on trade unions antagonising the government could put him in danger.

Giulio Regeni, originally from Italy, went missing on 25 January as Egypt marked the anniversary of the 2011 Arab Spring revolution that toppled Hosni Mubarak amid high security measures. Regeni's half-naked body was found in a ditch on the outskirts of the capital on 3 February, showing signs of torture. The 28-year-old PhD student was in Cairo for a research project on the Egyptian economy, with particular focus on independent trade unions – a sensitive topic in a country where the military-backed government has been violently repressing all opposition.

Unions were also the subject of the last of a series of articles he penned for Italian daily Il Manifesto, which styles itself as a 'communist newspaper'. In it Regeni told of attending an Independent Union meeting, which he said was defiantly restarting its activities despite pressure from authorities.

"[President] Sisi has obtained control of the parliament with the highest number of police and military in the history of the country, while Egypt lies at the bottom of all world rankings on press freedom. Yet independent trade unions do not give up," he wrote in the piece that was republished by Il Manifesto on 5 February.

The newspaper said they received the article in early January and Regeni required for it to be published under another name. "He feared for his safety," Il Manifesto wrote in an editorial. "From this insistence repeated several times in his emails, we understood he was very worried." The student's ties with activists and opposition figures were known to authorities, according to another Italian daily, La Stampa, which cited anonymous sources as saying he was "under surveillance". The paper also claimed Regeni attended a protest Cairo's twin province of Giza the day he vanished.

The man of Fiumicello, near Udine in Italy's north east, was last seen in the Dokki district of Cairo, where he lived, as he left home to head to a friend's birthday party in Bab Al Louq, near Tahrir Square. The protest hotspot was virtually under lockdown on 25 January, with a heavy police presence deployed to avoid demonstrations. The circumstance soon sparked fears Regeni had been caught up in a police swoop on anti-government demonstrators. His body was retrieved by the side of the Cairo-Alexandria Road in the 6 October suburb of western Cairo. Prosecutor Ahmed Nagi told AP that "all of his body, including his face" sported signs of violence and torture, including multiple stab wounds and cigarette burns, suggesting what he called a "slow death."

Earlier, authorities in Giza had seemingly dismissed the death as the result of a road accident. Khaled Shalabi, the director Giza general investigations administration, told local media the death was not suspicious, while his deputy Alaa Azmi was quoted by AP as saying Regeni's injuries were "bruises and cuts" and that a preliminary forensic analysis didn't mention any burns.

The Italian foreign ministry summoned the Egyptian ambassador demanding a thorough investigation in cooperation with a team of Italian and Interpol investigators that is due to arrive in Cairo on 5 February.