JERUSALEM -- Prime Minister Benjamin Netanyahu on Sunday defended his government's handling of an Australian-Israeli who was held under a pseudonym for months in a maximum-security prison until he committed suicide in 2010, suggesting that the threats his country faces justify the extraordinary measures and the secrecy shrouding the case.
"We are not like other countries," Mr. Netanyahu told his cabinet, in his first public comments on the case of Prisoner X, which made headlines on at least three continents last week. "We are an exemplary democracy and maintain the rights of those under investigation," he said. "However, we are more threatened and face more challenges; therefore, we must maintain proper activity of our security agencies."
In the face of growing calls from politicians and the public for investigations into the prisoner's death and a court order that barred the local news media from reporting about it for more than two years, the prime minister said, "Let the security forces do their work quietly so that we can continue to live in security and tranquillity in the state of Israel."
Prisoner X, the subject of Israeli news reports in 2010 that were quashed by the broad court order, was identified by an Australian television report last week as Ben Zygier, a 34-year-old lawyer and father of two who grew up in the Melbourne area, immigrated to Israel as a young man, served in the military and may have worked for the Mossad, Israel's intelligence agency. Arrested in February 2010, and held pending trial on charges that have been described only as serious and relating to national security, Mr. Zygier was considering a plea bargain when he apparently hanged himself with a shirt in the bathroom of his cell.
News reports here and in Australia have suggested that Israel detained him because he was about to reveal information about the Mossad's use of foreign passports, and that he helped set up a Mossad front company in Europe that sold electronics equipment to Iran. A Kuwaiti report saying that he was involved in the 2010 assassination of a Hamas official in Dubai has been dismissed by several people with knowledge of the case.
An Israeli Justice Ministry investigation that declared Mr. Zygier's death a suicide is expected to be released in the coming days, but several Israeli lawmakers and watchdog groups have demanded further inquiries by the attorney general and the state comptroller. And Australia's foreign minister said Sunday that he had asked Israel to cooperate as he and his staff look into the matter.
"We want to give them an opportunity to submit to us an explanation of how this tragic death came about," the minister, Bob Carr, told reporters in Sydney. "The key is to get all the information."
Nahman Shai, a member of Parliament from the Labor Party, said Australia's investigation should force Israel to look closer at the behavior of all involved. "We are witnessing oversights in various aspects of the case that include intelligence, legal, public, media and parliamentary," Mr. Shai said Sunday. "The Australian government will publish the information it has and again make Israel appear irrelevant to the international community and the Israeli public."
Two of Mr. Shai's colleagues, meanwhile, called for the formation of a parliamentary committee to investigate the case. And many Israelis joined social-media campaigns that are demanding more information.
"No Israeli citizen will be able to sleep comfortably in a country in which an affair such as Prisoner X can take place," wrote Uri Misgav, a blogger for the left-leaning newspaper Haaretz, in a lengthy post. "The Israeli public deserves to know whether the Israeli prisons are holding on to Prisoner Y and Prisoner Z," he wrote. "The Israeli public deserves to be told how all of the monitoring mechanics failed and how such a systematic failure will not be repeated."
But Mr. Netanyahu seemed untroubled by the affair. "I rely completely on the security forces," he told the cabinet. "I also completely rely on the legal authorities."
"The overexposure of security and intelligence activity could harm, sometimes severely, state security," he added. "The security interest cannot be made light of, and in the reality in which the state of Israel lives, this must be a main interest."
This article originally appeared in The New York Times.