An Australian citizen held at the US military camp in Guantanamo Bay has said he has been beaten, kicked and offered the services of a prostitute.
David Hicks has complained about his treatment before
The claims were contained in David Hicks' affidavit, ahead of his trial scheduled for early next year.
But Australia's Attorney-General Philip Ruddock said the claims contradicted earlier statements by Hicks' lawyers.
There have been widespread reports of harsh conditions at Guantanamo, including bright lights and loud music.
The affidavit contains a number of abuse claims made by Hicks, the so-called "Australian Taleban".
They include beatings while being handcuffed and blindfolded, having his head slammed into concrete, being forced to run in leg shackles and being routinely deprived of sleep.
He said that he was offered the services of a prostitute for 15 minutes if he agreed to spy on other detainees, which he said he refused.
"I was told repeatedly that if I co-operated during the course of interrogations, I would be sent home to Australia after the interrogations were concluded. I was told there was an 'easy way' and a 'hard way' to respond to interrogation," he said in the affidavit.
Hicks also detailed abuse he had seen committed against other prisoners, including the use of dogs.
Mr Ruddock cast doubt on the claims.
"It sits a little uncomfortably with some of the earlier statements made by Mr Hicks' lawyers that certainly affirmed that while at Guantanamo Bay he had been humanely treated," he said.
The attorney-general said that Canberra had asked the US to investigate.
Hicks' lawyer Stephen Kenny said Australia should launch its own inquiry.
"Given the extent of the detail and the consistency of the various reports of ill treatment at Guantanamo Bay, there can be no doubt that these allegations are true," he said.
Hicks' lawyers are arguing that his military trial, scheduled for 10 January, should be dropped. The charges against him include conspiracy to commit war crimes, attempted murder and helping the enemy during the 2001 US-led war in Afghanistan.
Hicks has pleaded innocent to all the charges. The Muslim convert and former abattoir worker faces a maximum of life imprisonment.
He is one of two Australian citizens held at Guantanamo Bay.
The other, Egyptian-born Mamdouh Habib, was arrested in 2001 in Pakistan. His family denies he has any links with al-Qaeda, saying he was captured while looking for a school for his children.