Amid all the many blotted-out parts of Melbourne-born Mossad agent Ben Zygier’s life and story there are two glaring questions: what was his alleged sin and how did he manage to kill himself in Israel’s most secure prison cell?

Israel, like all nations, has had its share of traitors. Dr. Marcus Klingberg, the deputy director of the biological laboratory in Nes Ziona, spied for the Soviet Union for two decades. But there is no Aldrich Ames in the Mossad’s past.

Assuredly, there have been those, like Wolfgang Lotz, a German-born Israeli spy who deceived his handlers in Tel Aviv and took on a new identity while undercover, and Yehuda Gil, who, out of greed, passed on knowingly false information to the Mossad during the mid-nineties, seeding fears that Hafez Assad of Syria was planning an attack on Israel.

As far as is known, however, no one from within the ranks of the organization has, for money or out of ideological conviction, provided enemy agents with the sort of information that leads directly to the shedding of Israeli blood. This is on account of careful selection and constant monitoring of all personnel.

What is known of Zygier’s background — his family, his years of Jewish schooling, his aliya and army service, along with the fact that he was apprehended less than two weeks after speaking with a journalist and after the Australian Security Intelligence Organisation had questioned him – points in the direction of a Mordechai Vananu-type affair, one in which the Mossad takes extreme measures, including the abduction of an individual, in order to prevent damaging, and embarrassing, information from falling into the hands of a friendly state. (Former Dimona nuclear technician Vanunu was lured from the UK to Italy, drugged, and shipped back to Israel, where he was convicted of treason; unfortunately for the guardians of Israeli state security, that was after he had sold the “secrets of Israel’s nuclear arsenal” to London’s Sunday Times.)

But why, in the Zygier case, would Israel take extreme measures? And what did Zygier know?

Assuredly, about the Mossad’s use of foreign passports.

The initial connection with immigrants like Zygier is often slow and deliberate. The Mossad will monitor the individual, gaining a sense of his or her beliefs, convictions and intentions. After some time, an officer will approach a Jewish immigrant to Israel from, say, Australia and ask to borrow his or her passport or for the individual to renew it under a new, non-Jewish name. This happens not infrequently.

Such a person, though, would not be considered a Mossad agent by any means. An agent is someone who was selected and put through rigorous training. Zygier may likely have started his career as the former, been found suitable, and progressed to the latter.

As an agent, Zygier would have been privy to more sensitive information. Jason Koutsoukis, a Middle East reporter for The Age, wrote an article on February 27, 2010 in which he revealed that the ASIO was investigating three dual Australian-Israeli citizens for using their Australian passports in the service of the Mossad. Zygier, whom he called on the phone but did not name, was said to have an Islamic Republic of Iran stamp in his passport and all three were said to be working at a shell company in Italy that sold electronic equipment to Iran and other Middle East states.

Koutsoukis’s article was published five weeks after a large team of Israeli Mossad agents allegedly assassinated Hamas weapons dealer Mahmoud al-Mabhouh in his hotel room in Dubai. All of the suspected agents carried passports from friendly nations, including three from Australia, which sparked interest in the ongoing and unrelated investigation. Several days before publication of Koutsoukis’s article, and not long after they had spoken on the phone, Zygier was arrested. His subsequent trial, which was under way when he took his life on December 15 that year, was being conducted under the highly unusual circumstances of complete secrecy.

One can only hope that his fateful arrest, incarceration and prosecution were undertaken in order to save Israeli lives.

As for Zygier’s suicide, Judge Daphna Blatman Kedrai, the president of the Magistrates Court in the Central Sector — and the daughter of Yona Blatman, the state prosecutor during the 300 bus affair — took 18 months to investigate and establish the circumstances of his death.

It is incumbent on the Justice Ministry to reveal that report and to explain why one of the most legible forms of death — strangulation from hanging – took so long to investigate. What must be explained, too, is how it is that Zygier, in a padded and protected cell, designed specifically for the murderer of prime minister Yitzhak Rabin, devoid of all hooks or shelves, was able to take his own life. And the sooner the better.