Vasiljkovic, better known as Captain Dragan, told Sydney's Central Local Court on Wednesday his guilt was "predetermined" in Croatia, where he was being persecuted because of his political beliefs and nationality, the paper reported.
He told the extradition hearing his prosecution by Croatia for war crimes was retaliation for the prosecution of Croatian military commander Ante Gotovina by the International Criminal Tribunal for the former Yugoslavia.
"I am a sworn political enemy of the HDZ (Croatian ruling party) and I believe I will not survive to obtain a fair trial in Croatia should I be surrendered into their custody," Vasiljkovic said in a statement.
"I believe I will be killed or alleged to have committed suicide. I do not believe I will get a lawyer in Croatia to properly present my case. I am frightened if I raise these matters I will be tortured and killed."
Vasiljkovic, an Australian national with residence in Perth, was arrested on January on the basis of Croatia's request. He is suspected of committing war crimes in his capacity as a commander of Serb paramilitary units during the war in Croatia.
Earlier this year Vasiljkovic tried unsuccessfully to obtain release before Australia's High Court, claiming that his arrest was unlawful because Australia and Croatia did not have an extradition agreement. The hearing before the Sydney court will continue.