According to a front-page story in the SMH, the FBI is looking to build its case up against Assange, who was indicted by the US Justice Department in 2019 for exposing US war crimes by publishing classified documents he obtained from a source, a standard journalistic practice.

The report said that last week, the FBI contacted Andrew O'Hagan, a Scottish novelist who worked as a ghostwriter for Assange's autobiography. O'Hagan rejected the FBI request as he opposes the US's efforts to imprison Assange for his journalism.

"I would not give a witness statement against a fellow journalist being pursued for telling the truth," O'Hagan said. "I would happily go to jail before agreeing in any way to support the American security establishment in this cynical effort."

Assange's legal team was surprised by the FBI request, which came amid building pressure on the Biden administration to drop the charges against the WikiLeaks founder. A delegation of Australian lawmakers recently met with the US ambassador to Australia and called on Washington to free Assange, who has been held in London's Belmarsh Prison since the indictment.