Revealed: another secret incarceration of Israeli secret services agent

After revelations about Ben Zygier, 'Prisoner X No. 2' blamed for 'horrible security breach'

Ben Zygier, the suspected Mossad spy previously known only as Prisoner X

For the second time in less than six months, the secret incarceration of a member of the Israeli secret services has been revealed.

The new case, which follows that of former Mossad agent Ben Zygier, who hanged himself in the high security Ayalon Prison in 2010, is also understood to involve someone who worked for of the Jewish state's spy agencies. Both Zygier, and the other individual, were known only as 'Prisoner X' during their imprisonment. The second prisoner has not been identified.

There are still few details about the new case, which was revealed earlier today by the liberal Haaretz newspaper. However, Zygier's lawyer, Avigdor Feldman, told Israeli radio that the allegations facing the second prisoner were much more severe.

"This affair points to far more severe failures than the ones committed by the defense [sic] establishment in Zygier's case," he said. "Regarding Zygier's case, the authorities that recruited him didn't understand who they were dealing with and weren't aware of his conduct. Okay - that's a failure. Prisoner X number two is an entirely different story - a horrible security breach. When I heard the story, as an Israeli citizen I was shocked, and the subject was completely silenced by lawyers who enjoy close ties with the establishment. Whoever opens this affair will be doing the country a great service."

It is believed that Zygier - disappointed by his superior's lack of willingness to hand him more interesting work - decided to try and impress his bosses and turn a leading member of the Lebanese group Hezbollah. He was then skilfully played to the extent that he ended blowing the cover of two double agents that had provided information to Israel.

Israeli officials have not commented on the case and like in Zygier's case, are unlikely to offer any insight, although it is believed that unlike in Zygier's case, the second Prisoner X had been convicted of whatever crimes he was accused of. It is not clear what has become of the second Prisoner X, but it is thought that he may still be being held at Ayalon prison.

Mr Feldman said that assumptions could be drawn from a detainee being classified as 'prisoner X'.

"They are Israeli, they work in institutions linked to security whose activities are shrouded in secrecy," he said. "And their detention demonstrates the failure of these organisations which are not capable of preventing offences such as those for which these agents have been arrested," he said.

The disclosure that at least two of its spies are alleged to have committed grave crimes against their own state is a huge embarrassment to Israel and the fact that a second Prisoner X is guaranteed to raise questions about whether there yet more people being held in similar circumstances.