Last month, many were spellbound when a story broke about Ben Zygier, forever known now as Prisoner X, whose young life ended by suicide in a supermax cell in Israel in 2010. Writing for Tablet, Elissa Goldstein chronicled how the revelation of Zygier’s demise had not only rocked his hometown of Melbourne, where his family is prominently involved in the Jewish community, but much of the world as the details of the shadowy tale emerged.

The story has all the hallmarks of a classic spy novel: forged passports, espionage, information suppression, and accusations of treason. But the tale of Prisoner X—who died under mysterious circumstances in 2010 in solitary confinement, having allegedly hanged himself in the maximum security cell built for Yitzhak Rabin’s assassin—is not only riveting for its John Le Carré flourishes.

At the time that Zygier’s identity was revealed, all the narrative pieces fit into a mosaic that, while constructing a biography and a mystique, failed to bring into focus a more important understanding: why? That picture has become clearer following a report by Der Spiegel, which claims that Zygier–following a demotion of sorts–had mistakenly given up the identities of some of the most high profile Israeli spies in Lebanon while trying to establish new contacts and prove himself to the Mossad.

In the process he came in contact with Hezbollah supporters, Spiegel said, and while trying to convince them to work for Mossad, disastrously spilled highly sensitive information.

This included the names of Lebanese nationals Ziad al-Homsi and Mustafa Ali Awadeh, who were arrested in May 2009 on charges of spying for Israel and later sentenced to several years of hard labour.

The report said Israeli security authorities had told Zygier after his arrest that they wanted to make an example of him and demanded a prison sentence of at least 10 years.

At the time, it was considered one of the biggest setbacks in the history of the Israeli intelligence community. According to the report, it was believed that Ziad al-Homsi, a prominent figure in Lebanon, was so treasured an asset that the Israelis believed he could lead them to Hezbollah leader Hassan Nasrallah.