JERUSALEM — The story had all the trappings of a spy thriller: an anonymous prisoner linked to Israel’s secret service, Mossad, isolated in a top-security wing originally built for the assassin of a prime minister. A suicide — or was it a murder? — never officially reported. A gag order that barred journalists from even acknowledging the gag order. And a code name to rival 007: Prisoner X.

The first reports about the death of Prisoner X leaked out in 2010, both in Israel and the United States, where a blogger identified the mystery man as a former Iranian general. Government censors immediately forced an Israeli news site to remove two items related to Prisoner X — and journalists were interrogated about it by the police.

On Tuesday, after an extensive Australian television report identifying Prisoner X as an Australian father of two who became an Israeli spy, the prime minister’s office summoned Israeli editors to a rare meeting to remind them of the court order blocking publication of anything connected to the matter.

It remains unclear what Prisoner X might have done to warrant such extreme treatment — and such extreme secrecy, which human rights groups have denounced as violating international law. What is clear is that the modern media landscape makes the Israeli censorship system established in the 1950s hopelessly porous: the Australian report quickly made the rounds on social media, prompting outraged inquiries from opposition lawmakers on the floor of Parliament.