Prisoner X unveiled? Man who killed himself in Israeli jail-within-a-jail 'was Australian Mossad agent'

Ben Zygier from Melbourne is thought to be Israel's infamous Prisoner X (ABC TV)

A prisoner so anonymous that apparently not even his jailers knew his name or why he was locked up was a 34-year-old who had been recruited by Mossad, according to the Australian Broadcasting Corporation.

He committed suicide in the Israeli jail in 2010 after being held for months, the ABC reports. It says evidence strongly suggests he was Ben Zygier, who used the name Ben Alon in Israel and had moved from Melbourne 10 years earlier. The reason for his imprisonment remains a mystery.

ABC reports: "The death goes part of the way to explain the existence in Israel of a so-called Prisoner X, widely speculated in local and international media as an inmate whose presence has been acknowledged by neither the jail system nor the government."

It says the case is regarded as one of the most secretive secrets of Israel's intelligence community and that the Prisoner X cell was a jail within a jail at Ayalon Prison in the city of Ramla.

"When an Israeli news website reported that the prisoner died in his cell in December 2010, Israeli authorities removed its web pages."