Australian musician Willy Zygier told ABC Local Radio in Melbourne that the case was a "tragedy", but would not shed any light on whether his nephew, Ben Zygier, was Israel's infamous "Prisoner X."
"I have no idea what is true, what isn't true," he said. "All I know is there's a family tragedy. Every suicide is a tragedy. That's all I've got to say," he said.
"I don't know what else to say. There's nothing else to say."
According to Willy Zygier, "Ben's parents are in mourning. I don't know if they'll talk. And I'm a humble musician. I don't know anything."
Ben Zygier's grave in Melbourne (Photo: EPA)
Zygier's family has previously declined to speak to the ABC, and friends and acquaintances approached by Foreign Correspondent in Melbourne had also refused to comment.
Australian television network ABC aired an investigation on Tuesday revealing that Ben Zygier, an Australian national who was held in complete isolation at the Ayalon Prison in Ramla, had died in a high-security cell in late 2010. According to official documents, he committed suicide.
The report claimed that in the years before his arrest the man had worked for the Mossad spy agency. The State, the report said, made efforts to keep the case – and the prisoner's existence – a secret.
The 28-minute program revealed that Ben Zygier, who was in his 30s when he died, used the name Ben Alon while living in Israel. He was married to an Israeli woman and had two small children.
According to the investigation, the prisoner was found hanged in a cell which was equipped with state-of-the-art surveillance systems installed to prevent suicide.