He was one of three Australian Jews who changed their names several times to obtain new passports allowing them to travel to Europe and the Middle East in their capacity as Mossad agents. Mr Zygier is believed to have drawn the attention of Australian agents because of the frequency with which he changed names. In fresh revelations, ABC said Mr Zygier had established a communications company in Europe, employing two other Australian dual nationals. The venture exported electronic components to Iran as well as to Arab countries. Mr Zygier returned to Australia frequently with his Israeli wife and two children and on one occasion enrolled on a business master degree course at Monash University in Melbourne. It was one such visit that brought him into contact with Australian intelligence agents, which later came to the attention of Mossad. Mossad's relations with Australia's intelligence agency had already soured before Mr Zygier death in 2010 after it was accused of using Australian passports in the assassination of a Palestinian arms dealer, Mahmoud Mabhouh in Dubai earlier in the same year. Ronen Bergman, an Israeli intelligence specialist currently writing a book on the history of Mossad, said the use of dual citizens was a "major necessity" for the agency's work. "If Israel were not to use people with dual citizenship, then Mossad would need to give up the services of many people and you would end up with an intelligence agency that's unable to function," he told The Daily Telegraph. People with dual citizenship are attractive because the most important characteristic that any operative needs is the ability to work undercover with a false identity. This is something you only obtain if you were brought up in, or spent a lot of time in, a country outside Israel. The Israeli newspaper Yedioth Ahronoth reported on Monday that shortly before his death, Mr Zygier's lawyers had been in plea bargain negotiations with officials that would have him seen him given a jail sentence of between 10 and 20 years. The anticipated publication of a report into the affair, written by a magistrates court judge, Dafna Baltman-Kadrai, has been delayed because of a dispute between Israel's justice ministry, which favours disclosure, and the security establishment, Maariv newspaper reported. Israel's prime minister, Benjamin Netanyahu, commenting on the affair for the first time, said on Sunday that "overexposure" of intelligence matters could "badly damage" state security interests.