Israel's top civil and human rights lawyer, Avigdor Feldman, last saw him alive. "They asked me to see him, and a day after that he was gone," he said.
"When I saw him, I saw no signs that he was going to kill himself. He sounded rational, and he asked pertinent legal questions that I can't expand on."
In 2011, the Association for Civil Rights in Israel (ACRI) petitioned to have Israel's gag order lifted. Israel's Central District denied it. A Supreme Court appeal followed.
Classified information was revealed in court. Justices advised ACRI to strike its appeal. It did so to avoid a detrimental legal ruling.
ACRI's chief legal counsel, Dan Yakir, said he first learned about an inquest into Zygier's death in court. Few details were revealed.
"As for the question of negligence," he asked, "how can it be that prisoner held in (Israel's) most secure (prison) commited suicide?"
Saying so doesn't pass the smell test. He was closely monitored 24-hours a day. He was never out of sight.
Haaretz provided extensive coverage. News of Zygier's death shocked his parents, it said. On February 13, the Australian Age newspaper said he "was under investigation by Australian intelligence months before" Israel arrested him.
Allegedly it was for "fraudulent use of his Australian passport for espionage purposes."
Israel's gag order imposed censorship. Doing so was a "pathetic attempt to turn back the clock" to pre-Internet days.
Prisoner X reflects a classic case of "Israeli failure." It shows "Israel's most sensitive government agencies are not functioning."
If information now known is right, Israel's Prison Service, Justice Ministry, attorney general, courts, Mossad, prime minister, and perhaps others share blame.
More may revealed after Israel partially lifted its gag order. Australia's ABC said Zygier emigrated to Israel in the late 1990s. He took the Hebrew name Ben Alon. He performed IDF service. He worked for Mossad before he died.
He was recruited in 2000. He served for a decade. He "undert(ook) assignments in enemy states using his Australian passport."
He was "one of three Jewish Australians who were working for a (European-based) front company set up by Mossad." It recruited agents and sold electronics to Iran.