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

According to the Guardian report, the source gave Koutsoukis 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, Koutsoukis said, he contacted Zygier at his home in Jerusalem and confronted him with allegations of the story.

“The company did exist,” Koutsoukis 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 Koutsoukis’s account, Zygier changed his name four times in Australia. Although Australian law permits changing one’s name legally once a year, Australian authorities grew suspicious and were beginning to close in on Zygier, Koutsoukis said.

Koutsoukis reported in 2010 that two Australian intelligence sources told him that the Australian Security Intelligence Organization was investigating three Australians who had emigrated to Israel in the last decade and who had changed their names and requested new passports.

“The three Australians share an involvement with a European communications company that has a subsidiary in the Middle East. A person travelling under one of these names sought Australian consular assistance in Tehran in 2004,” he reported at the time in the Sydney Morning Herald.

After a Mossad hit squad reportedly killed senior Hamas weapons importer Mahmoud al-Mabhouh in Dubai in January 2010, Koutsoukis decided to confront Zygier and telephoned him, the Guardian report said.

“When I spoke to him he was incredulous at first and said f*ck off – but what was interesting was that he did not hang up,” Koutsoukis 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.”

Koutsoukis said he also had a series of bizarre exchanges with the CEO of the alleged front company. He reported that the company’s office manager confirmed that one of the three Australians was being monitored by the ASIO.

“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 later told the Guardian.

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

Zygier was reportedly imprisoned later in 2010, a fact the Australian spy agency was aware of, according to The Australian. Australian Foreign Minister Bob Carr on Thursday acknowledged to the Australian Senate that Canberra was given assurances by Israel that Zygier’s rights would be respected.

“The Australian government was informed in February 2010 through intelligence channels that the Israeli authorities had detained a dual Australian-Israeli citizen – and they provided the name of the citizen – in relation to serious offences under Israeli national security legislation.” he said.

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

An Israeli TV 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 Koutsoukis.

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, a member of a prominent Melbourne Jewish family, was detained in solitary confinement on suspicion of committing treason, according to Army Radio reports quoted in The Australian Wednesday.

Israel’s Justice Ministry said in a statement that an extensive investigation into his death ruled it a suicide six weeks ago.

Reports this week said Zygier was 34 when he died, on December 15, 2010. His remains were sent to Melbourne for burial shortly afterward.

His family refused to comment on the case this week. “I really don’t want to talk about it,” his father said. “I’ve lost my son.”