Israel’s mysterious “Prisoner X”, who hung himself in suspicious circumstances in Ayalon Prison in 2010, has been revealed as a Jewish man from Melbourne, according to the explosive findings of a television investigation.

The Australian Broadcasting Corporation’s Foreign Correspondent programme claimed this week it had “compelling evidence” that the inmate incarcerated for several months in the suicide-proof cell was Ben Zygier.

According to documents obtained by the investigation, Zygier was 34 when he died on December 15, 2010 from “asphyxiation by hanging”. He was educated at King David and Bialik College, two Jewish schools in Melbourne, was a member of Hashomer Hatzair youth movement, a graduate of the Machon leadership programme in Jerusalem and spent several months on Kibbutz Gazit. He then worked at Deacons law firm in Melbourne before emigrating to Israel in 2000 and assuming the name Ben Alon, according to acquaintances. Zygier had another Australian passport under the name Ben Allen, ABC’s report claimed. He lived in Raanana with his wife and two children.

Although the report said it “understood” Zygier was connected to Mossad, it offered no conclusive proof.

Australian Foreign Affairs Minister Bob Carr ordered a review of the case on Wednesday in light of the investigation. It is understood the first the government was unaware that an Australian citizen had died in an Israeli jail, although it emerged on Wednesday that Israel had informed an Australian diplomat of Zygier’s jailing but that he had not passed on the information.

The broadcast on Tuesday night threw Melbourne’s tight Jewish community into a frenzy of speculation. One friend of Zygier who was on Kibbutz Gazit with him in 1994 said: “Ben never struck me as someone who was stable. I could never imagine someone like that being good for Mossad”.

Zygier’s mother, Louise, worked at Monash University. She left her post soon after Zygier’s death. Her husband, Geoffrey, was executive director of the Jewish Community Council of Victoria at the time of the death and is now the executive director of B’nai B’rith’s Anti-Defamation Commission.

In Israel, a gag order issued by the Petach Tikva District Court had been in effect since 2010 on any detail regarding “Prisoner X”. When news organisations covered the story on their websites on Tuesday, they were ordered by Military Censorship to take them down.

A few hours later, MKs Zehava Galon, Dov Hanin and Ahmed Tibi used parliamentary privilege to ask the Justice Minister about the reports. The session was broadcast live and the Israeli media was free to report on the questions. By the next morning, a new gag order was put out allowing the reporting of details that had been published outside Israel. On Wednesday night, Israeli authorities released a report saying that the death of Zygier had been the subject of a two-year probe, wound up in 2012.