Torture and abuse
Hicks, 31, who has been in US custody at the Guantanamo military prison for five years, has complained of torture and abuse.
"After five years, the US has not charged David with a single war crime"
Major Michael Mori, defence lawyer
He said he had been shown a photo of a battered fellow inmate, and was told he would be sent to Egypt for similar treatment if he did not co-operate, Australian media said on Friday.
Hicks said the anxiety caused by months of abuse forced him to "say anything" to US military interrogators.
The US military accuses Hicks of supporting terrorism by attending al-Qaeda training courses, conducting surveillance on the US embassy in Kabul, and briefly fighting US and coalition forces in Afghanistan.
A second charge of "attempted murder" was not advanced. An attorney for Hicks said the charge of providing material support has never existed in the laws of war and that his client had "no hope" of getting a fair trial.
|Hicks, pictured during training in Kosovo in |
1999, is accused of supporting terrorism [AP]
"All this time, we have been told that David had to be tried by military commission rather than in a federal court because the offences were war crimes," Major Michael Mori, defence lawyer in the Pentagon's military commissions office, said.
"But after five years, the US has not charged David with a single war crime."
The Pentagon appoints US military lawyers to detainees facing charges at Guantanamo.
The military charges that Hicks took part in operations against coalition forces during the early stages of the US-led war in Afghanistan in October 2001.
He guarded a tank outside of Kandahar airport for a week and while there trained others, according to the charges.
Hicks then moved to Kabul and Kunduz, looking for combat opportunities, the US military said.
In Kunduz, he joined for two hours a group of al-Qaeda and Taliban members fighting US-led forces, according to the documents.
The next day, Kunduz fell to US forces and Hicks fled, only to be captured in Afghanistan by Northern Alliance forces while trying to reach Pakistan, the documents stated.
The US has been criticised worldwide for the continued detention at Guantanamo Bay of people the Pentagon says are al-Qaeda and Taliban members.
Many have been held for about five years without being charged.
The Pentagon on Thursday said it had transferred five detainees to Afghanistan and Tajikistan, bringing the number of remaining detainees to 385.