Rights groups and the family of the murdered Italian student Giulio Regeni have heavily criticised an arms deal between Italy and Egypt worth an estimated $1.2bn (£960m). Regeni’s mutilated body was found by the side of a major road on the outskirts of Cairo in early 2016. His murder remains unsolved, but there are widespread suspicions that he was abducted, tortured and killed by Egyptian security forces. Last Thursday, Italy’s government approved the sale to Egypt of two frigates built by the Italian state-controlled shipbuilder Fincantieri, marking a decisive break with a period of tepid relations between the two countries. The prime minister, Giuseppe Conte, gave final approval after months of secret negotiations, according to the Italian newspaper La Repubblica. The Fincantieri sale is part of a much larger potential Egyptian-Italian weapons deal that is estimated to be worth between €9bn and €10bn and comprises four more frigates, 24 Eurofighter Typhoon jets, 24 M-346 trainer aircraft and a military satellite. If signed, it would be the largest arms deal in Egypt’s recent history and one of the largest sales by Italy since the second world war. “The Italian state has betrayed us,” Regeni’s mother, Paola Deffendi, said in an interview aired on Friday on the television show Propaganda Live. “We were betrayed by friendly fire, not by Egypt. One cannot expect to struggle against one’s state for justice. This is a betrayal for all Italians who believe in the inviolability of rights.” Erasmo Palazzotto, who leads a parliamentary commission investigating Regeni’s death, said that in light of the latest significant developments the commission wanted to speak to Conte urgently. Giorgio Beretta, an analyst of the arms trade for the website Osservatorio Diritti, said: “What country would ever sell an entire military arsenal to an autocrat who allows the murder of one of its citizens?” Riccardo Noury, a spokesman for Amnesty International in Italy, told the Guardian that what was described as the deal of century was for him “the shame of the century”. “And this would be only the starter of a deal that could reach €9bn,” he said. “We demand that this sale be voted on by parliament. If not, we reserve the right to take legal action.” There has been little progress in efforts to force Egypt to bring Regeni’s killers to justice. Despite pressure in Italy from the country’s public prosecutors, some of its MPs and members of the public, other parts of the Italian state have moved towards closer relations with Egypt in the years since his death. Italy’s foreign ministry reinstated its ambassador to Egypt in 2017, a year after their withdrawal owing to Egyptian inaction over the Regeni case. The Italian oil and gas major Eni also made a $16bn investment in Egypt’s Zohr gas field. The lower house of the Italian parliament cut relations with Egypt in 2017, saying they would resume when the Egyptian authorities conducted a proper investigation into the death and held a trial. Yet Conte’s cabinet ignored parliamentary pressure and approved the sale of the two frigates. Egypt is also facing renewed criticism from Italy after the arrest and alleged torture of Patrick Zaky, an Egyptian masters student at the University of Bologna who is a researcher at the Cairo-based Egyptian Initiative for Personal Rights. Zaky remains in detention since being arrested on his return to Cairo, and his case has drawn parallels with Regeni’s disappearance. Last week, the Italian foreign minister, Luigi Di Maio, reassured a parliamentary inquiry into the frigate deal that Italy was continuing to follow Zaky’s case. It remains unclear how Egypt will pay for the warships, let alone the larger potential deal. According to the media in Italy, €500m will reportedly come via an export financing loan from Italian investment bank Cassa Depositi e Prestiti. Egypt’s arms imports have tripled in recent years, making it the world’s third largest arms importer, according to the Stockholm International Peace Research Institute. Meanwhile, Egypt accepted a $2.8bn emergency loan from the International Monetary Fund in May, intended to help the country’s economy overcome the challenges posed by the Covid-19 pandemic. It is the latest in a series of large loans intended to support the economy in Egypt, where despite large numbers of the population being affected by increasing austerity measures, the country’s leaders have poured billions in mega-projects such as a new capital city in the desert.