A journalist who interviewed an Australian Jew shortly before he was detained by Israeli authorities and came to be known as "Prisoner X" said on Thursday the man strenuously denied being a spy.
The 34-year-old man, who was identified by Australia's ABC as Mossad agent Ben Zygier, died in a secret prison near Tel Aviv in 2010 in a case Israel covered up using gag orders, eventually breaking its silence following the report.
Israel on Thursday confirmed it jailed a foreigner in solitary confinement on security grounds as Australia admitted it knew one of its citizens had been secretly held.
But freelance journalist Jason Koutsoukis, formerly media group Fairfax's Middle East correspondent, told ABC that Zygier convincingly denied that he was a spy on the "three or four" occasions Koutsoukis interviewed him.
Koutsoukis said he was tipped off by an Australian intelligence source in October 2009 about three dual-national citizens who had changed their names and were suspected of spying for Israel using their Australian passports to travel to countries like Syria, Iran and Lebanon.
"He listened politely to what I had to say and it was, even to me, an outlandish story... And at the end of what I had to say, he responded and denied it as strenuously as he could possibly deny something like that," Koutsoukis.
"He was just incredulous and then we wound up the conversation."
The reporter added that he thought it was possible his interviews with Zygier were under Israeli surveillance.
"There were a couple of strange incidences which happened around my home in Jerusalem, which I didn't take seriously at the time, but in hindsight it is possible that they were monitoring our conversations," he said.