Jason Katsoukis’s investigation into Ben Zygier, aka “Prisoner X,” who was said to have committed suicide in Ayalon Prison in 2010, began in 2009, when an anonymous source fed the Australian Fairfax reporter information regarding a Mossad front company operating in Europe and selling goods to Iran, the Guardian reported Wednesday evening.

According to the report, the source gave Katsoukis the names of three Australians with joint Israeli citizenship who were working for the Mossad. The alleged agents were said to be selling electronics to Iran through a company based in Europe.

In 2009, Katsoukis said, he contacted Zygier at his home in Jerusalem and confronted him with allegations of the story.

“The company did exist,” Katsoukis was quoted as saying. “I also managed to establish that Zygier and another of the individuals had worked for it. I wasn’t able to confirm the third name.”

According to Katsoukis’s account, Zygier changed his name four times in Australia. Australian authorities, Katsoukis said, were becoming suspicious and were beginning to close in on Zygier.

After the 2010 Mossad hit squad killed senior Hamas operative Mahmoud al-Mabhouh in Dubai, Katasoukis decided to confront Zygier and called him, the report said.

“When I spoke to him he was incredulous at first and said fuck off – but what was interesting was that he did not hang up,” he said. “He did soundly genuinely shocked. But he listened to what I had to say.

“I still wonder why he didn’t hang up. He denied everything however. He said he hadn’t visited the countries it had been claimed he had. I tried calling again but in the end he told me to buzz off.”

Katsoukis said he had a series of bizarre exchanges with the CEO of the alleged front company.  

“He seemed a bit weird. He denied all knowledge of what I was talking about, but then wanted to talk to me again and make an arrangement to meet up,” he said.

Katsoukis claimed that a senior government official later confirmed the story, even though he had the opportunity to refute it.

Zygier was apparently imprisoned later that year.

Fairfax eventually excluded news of the front company from its report on the three Australian citizens who had allegedly been spying for Israel. In his interview with the Guardian, Katsoukis did not say why that information didn’t make it to press.

An Israeli report Wednesday said the Australian security services had “burned” Zygier by leaking the story to an Australian journalist. The report didn’t divulge whether the journalist in question was Katsoukis.

Israel on Wednesday night confirmed that a suicide of a security prisoner occurred at the prison in late 2010, and ordered an investigation into possible negligence by the prison authorities.

Zygier was 34 when he died. His remains were sent to Melbourne for burial shortly afterward.