JERUSALEM – An Israeli secret agent whose death in Israel's highest security prison was kept secret for nearly two years may have inadvertently revealed details of one of Israel's most important intelligence-gathering networks, according to reports on the case published Monday.

Why Mossad agent Ben Zygier, who was known until earlier this year only as Prisoner X, was jailed had been a lingering mystery of the case. Zygier spent nearly a year in solitary confinement so intense that not even his jailers knew his real name before he died, allegedly by suicide. Israeli officials added to the mystery by banning journalists from reporting on the case after Zygier was found dead in his cell in December 2010.

A variety of theories for his imprisonment had been floated, including that he'd sold intelligence to Iran, was preparing to publish a tell-all about the Mossad or had turned double agent for a government in the Persian Gulf. There were even suggestions that he'd been detained because he'd revealed details of how Israel used foreign-born Israelis in its intelligence-gathering. Zygier was born in Australia.

But the new reports suggest that Zygier was a desk-bound agent who botched a self-initiated effort to turn a Hezbollah operative into an Israeli agent, instead ending up revealing the identities of Israeli operatives in Lebanon.

According to Fairfax Media, Australia's largest newspaper publisher, and Germany's Der Spiegel magazine, which conducted a joint investigation into the case, Zygier unwittingly handed over Israeli intelligence files to a man he thought he was turning into a double agent for Israel.

Zygier, who grew up in Melbourne in a strongly Zionist family, immigrated to Israel and was recruited to the Mossad in 2003. At first he worked in Europe, where he took an accounting job in a company with links to the Middle East. In 2007 he was ordered back to Tel Aviv and assigned to a desk job because his bosses were unhappy with his work, according to the Der Spiegel report, which was written by Israeli journalist Ronen Bergman.

The Mossad had recently decentralized its computer system so that lower-level agents would have access to greater amounts of data, and under that system Zygier was able to access files on various topics. He used that access, Bergman said, to try to recruit an Eastern European man known to be close to the Lebanese Shiite Muslim militant group Hezbollah, which has fought several wars against Israel.

In his bid to recruit the man, Zygier revealed the names of Israel's top two Lebanese informants, Ziad al-Homsi and Mustafa Ali Awadeh. Soon afterward, the two men were arrested and sentenced to 15 years in prison.

"This is not a story of treachery; this is a sad story of an avid Zionist who emigrated from Australia to Israel and wanted to be a Mossad hero," Bergman told the Australian Broadcasting Corp. in an interview.

"This was his life's dream, and at the end of the day it ended in tragedy, where he was so trying to prove himself he got himself mixed up in this fiasco operation."

The Mossad first brought Zygier in for questioning when it was discovered that he'd bragged to his friends and fellow students in Australia about his work as a Mossad agent. During questioning, he broke down and revealed his contact with the man in Europe. When he was arrested in early 2010, Zygier was carrying a CD loaded with more intelligence files, which he might have planned to pass on to his Hezbollah contact, said the Sydney Morning Herald, a Fairfax outlet.

Israeli officials have refused to comment on the details of the case, but it was revealed in a court file released earlier this year that Zygier had agreed to be held in jail under a pseudonym and that his lawyer was negotiating a possible deal that would include a 10-year jail term for his client. Zygier allegedly killed himself by constructing a noose in his shower in December 2010.

While they couldn't confirm the Fairfax and Der Spiegel report, Israeli intelligence officers told McClatchy Newspapers that the story "rang true" and that it had long been rumored that a Mossad insider had bungled Israel undercover operations in Lebanon.

"Fingers were not pointed, not exactly, but the way in which our operatives in Lebanon were arrested and the amount of detail that was known about them made it clear that someone from our side had given up the intelligence," said one Mossad officer who retired from his post late last year and spoke on the condition of anonymity. "The Lebanese authorities and Hezbollah don't normally rout out our men on the ground quite so easily."

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