Rod Barton, a former senior analyst for Australia's Defence Intelligence Organisation (DIO) said on Sunday that he had personally interrogated an Iraqi detainee at Camp Cropper, a US centre which held "high value" prisoners.
"Someone was brought to me in an orange jumpsuit with a guard with a gun standing behind him," Barton told Four Corners, a news programme to be broadcast later on Monday on Australian Broadcasting Corporation television.
"Of course I didn't pull any fingernails out but I think it's misleading to say no Australians were involved - I was involved," he said.
The long-time Iraq weapons inspector also said he had witnessed and reported the alleged abuse of Iraqis by their US captors.
"Of course I didn't pull any fingernails out but I think it's misleading to say no Australians were involved, I was involved"
former Australian spy
Last year after revelations that US soldiers were abusing Iraqis in Baghdad's Abu Ghraib prison, the Australian government steadfastly denied that any Australians were involved in the
interrogation of Iraqi detainees.
Concerns were raised
Defence Minister Robert Hill testified in parliament that "Australia did not interrogate prisoners".
Barton said he raised concerns with an Australian defence official about the abuse of inmates at Camp Cropper before the mistreatment at Abu Ghraib became public, but no action was taken.
He said he had seen prisoners with bags over their heads in solitary confinement in tiny cells, some with abrasions on their faces which US officials said were the result of suspects resisting arrest.
Barton said in one case he suspected a prisoner was beaten to death.
Barton's claims come a day after an Australian who was recently released after three years detention by the US military as a terrorist suspect said an Australian diplomat watched him being tortured by US soldiers.