* Australian immigrant reported to be disgraced Mossad spy
* Eluded isolation cell cameras
* Israelis deny wrongdoing in affair queried by Canberra
By Dan Williams
JERUSALEM, Feb 19 (Reuters) - Israel released details on Tuesday about the 2010 jailhouse suicide of an Australian immigrant reported to have been a disgraced Mossad spy, saying he hanged himself in his cell and no foul play was involved.
The affair was kept under wraps until it emerged last week with an Australian television expose that identified the dead man as 34-year-old Ben Zygier, a likely Israeli foreign intelligence recruit held for suspected security offences.
Without explicitly naming Zygier, Israel has confirmed that at the time it had a dual citizen in custody and under alias to stem serious harm to national interests, on which it would not elaborate. The Dec. 15 date it gave for the detainee's death matched that etched on the Melbourne-born Jew's gravestone.
Easing a gag order, an Israeli court allowed the publication on Tuesday of the results of a judge's inquiry, completed two months ago, into the death.
The investigation showed the prisoner looped a wet sheet around his neck, tied it to the bars of a bathroom window in his cell and hanged himself, choking to death.
Israeli media reported the bathroom area was not covered, for privacy reasons, by closed-circuit television cameras that transmitted images from other parts of the isolation cell.
Ruling out foul play on the basis of medical and physical evidence, Judge Dafna Blatman-Kardai said entry to the cell was monitored by cameras and examination of their footage showed no one "intervened in causing the death of the deceased".
She said his family - which has not commented publicly on the case - agreed with the findings.
"A small amount of sedative was found in his blood. There was no alcohol or drugs. This does not change my determination ... about the cause of death," a forensic medical expert was quoted as saying in the judge's report.
Civil liberties groups and some lawmakers in Israel, protesting at the state censorship restricting local reporting on the case, have demanded to know whether Zygier's rights were violated by his months of incarceration, isolated from other inmates, and whether his death could have been prevented.
Those calls were echoed in Australia, where media suggested Zygier had been suspected of betraying Mossad missions to Canberra's spy services. Australia was angered in 2010 by the fraudulent use of its passports in the assassination of a Hamas arms procurer in Dubai, which the Gulf emirate blamed on Israel.
NEGLIGENCE IN QUESTION
In her report, the judge said there was prima facie evidence that the Prisons Authority had been negligent, noting that it had received special instructions on supervising the prisoner to prevent a possible suicide.
A Justice Ministry spokesman said state prosecutors would decide whether charges will be brought.
A source briefed on the affair told Reuters that Israel has since installed biometric detectors in the toilet stalls of high-risk prisoners, designed to summon guards within seconds should they stop breathing or display other signs of distress.
Responding to the media reports about Zygier, Israeli Internal Security Minister Yitzhak Aharonovitch told parliament on Monday that the detainee had received frequent family visits and been "supervised by mental-health support and treatment systems, both external and those of the Prisons Service".
Zygier also consulted with Israeli lawyers, one of whom, Avigdor Feldman, said he saw the married father of two shortly before his death to discuss "grave charges" on which he had been indicted, and the possibility of a plea bargain.
"I met with a balanced person ... who was rationally weighing his legal options," Feldman told Israeli television last week, adding Zygier had denied the charges against him.
"His interrogators told him he could expect lengthy jail time and be ostracised from his family and the Jewish community. There was no heart string they did not pull, and I suppose that ultimately brought about the tragic end."
Feldman declined to comment on an Israeli newspaper report that Zygier faced between 10 and 20 years in prison.
Deputy Prime Minister Dan Meridor on Saturday called Zygier's death a "tragedy" but said his treatment was justified. (Additional reporting by Maayan Lubell; Writing by Dan Williams and Jeffrey Heller; Editing by Mark Heinrich)