* Court stops short of confirming suicide was a Mossad spy
* Israelis chafe at censorship on story available over Web
By Dan Williams
JERUSALEM, Feb 13 (Reuters) - Israel broke its official silence on Wednesday over the reported suicide in jail of an Australian immigrant recruited to its spy service Mossad, giving limited details on a closely guarded case.
After appeals by local media chafing at Israeli censorship of a story broken by the Australian Broadcasting Corporation (ABC), a district court near Tel Aviv allowed publication of six paragraphs of sanctioned text - a de-facto preliminary account by the state.
The text said that an Israeli with an unspecified dual nationality had been secretly imprisoned "out of security considerations", only to be found dead in his cell two years ago in what was eventually ruled a suicide.
The district court did not confirm or deny ABC's unsourced findings that the dead man was 34-year-old Ben Zygier, an Australian who moved to Israel and may have been jailed in isolation over suspected misconduct while spying for Mossad.
Social media records showed that Zygier, who died in late 2010 and was buried in Melbourne, had been married with children. His relatives have declined all comment on the case.
The Israeli district court said the unnamed detainee had been held under the supervision "of the most senior officials of the Justice Ministry" and that his family had been informed of his arrest immediately after it took place.
After citing other legal monitoring mechanisms in the case, the district court said: "Beyond this no details can be published about the affair, for reasons of national security."
Israeli media had earlier quoted the ABC and other foreign reports about Zygier, dubbed "Prisoner X", some of which suggested he had been under investigation by Australia's security services on suspicion of using his native passport for Mossad missions in countries hostile to the Jewish state.
The possibility that a Mossad officer had been treated so harshly drew comparisons to known previous cases when Israel jailed turncoat spies under blanket secrecy, sometimes lasting years.
Israeli intelligence veterans said such measures reduced the risk of enemy countries where the detainees had served learning of their true identities and then tracing their activities in order to expose other spies still under cover.
Mossad is widely reputed to have stepped up its shadow war in recent years against Iran's nuclear programme, Lebanon's Hezbollah guerrillas, suspected nuclear procurement by Syria and arms smuggling to Palestinians through Dubai, Sudan and Egypt.
Yet the official secrecy over the Zygier report, reinforced by military censors, caused an outcry in Israel, where reporters noted that their compatriots were but a mouse-click away from learning about the case from foreign media on the internet.
In a highly unusual move within hours of the ABC broadcast, Israeli editors were summoned to an emergency meeting in Prime Minister Benjamin Netanyahu's office on Tuesday and asked not to publish a story "that is very embarrassing to a certain government agency", Israel's liberal Haaretz newspaper reported.
Haaretz ridiculed the gag order as outmoded and counter-productive, but one of the editors who attended the meeting, Yinon Magal of the Walla news-site, was more circumspect.
The explanation he had received for the secrecy, Magal told Israel's Channel 10 television, "persuaded me, overall, that there is a certain logic, albeit small, that there are considerations of national security and of human life here".
(Writing by Dan Williams; Editing by Mark Heinrich)