Osama bin Laden's former driver, Salim Hamdan, has pleaded not guilty at the opening of the first war crimes trial before a special military tribunal at the US base in Guantanamo Bay, Cuba.
“The trial has started and he pleaded not guilty,” said Cynthia Smith, spokeswoman for the US Defence Department. The trial is expected to take up to two weeks.
VIDEO: Guantanamo trial to begin
Mr Hamdan, from Yemen, is the first “enemy combatant” in Guantanamo from the US 'war on terror' to face a full-scale trial since the prison camp at the remote naval base was opened in late 2001.
He faces charges of “conspiracy” and “material support for terrorism,” and could receive life imprisonment if convicted by the controversial tribunals set up by President George W Bush.
Australian national David Hicks was to face a military trial in 2007 but pleaded guilty at a hearing before it began.
After being held without trial for five years, Hicks admitted to providing material support to terrorism as part of a deal that allowed him to return to his country where he served the remainder of his sentence.
Crucial test of tribunal system
The Pentagon is withholding the identities of the 13-member jury pool brought to Guantanamo over the weekend, but all are US military officers.
The trial is seen as a crucial test of the US's controversial military tribunal system.
The Bush administration set up the special military commissions in the wake of the September 11, 2001 attacks on the United States, saying terror suspects could not be adequately prosecuted in regular courts.
The military commissions were declared illegal in 2006 by the Supreme Court, only to be restored a few months later by the US Congress.
They have since faced a series of legal battles and hitches including a June Supreme Court decision that granted foreign terror suspects captured abroad the right to challenge their detention in US courts.
The indictment against Mr Hamdan, who is about 40 years old, alleges that he met bin Laden in the Afghan city of Kandahar in 1996 and “ultimately became a bodyguard and personal driver” for the al-Qaeda leader.
It alleges that he received training in the use of rifles, handguns and machine guns in an al-Qaeda camp and also “delivered weapons, ammunition or other supplies to al-Qaeda members and associates.”
Mr Hamdan was transferred in 2002 to Guantanamo – where he has spent much of his detention in isolation – and ordered tried by a military tribunal.
Lawyers for Mr Hamdan say he is not implicated in any terrorist activity even though he served as the al-Qaeda mastermind's driver.
They also argue that he was mistreated while in US custody and was subjected to sleep deprivation, including being awakened every hour by guards during a 50-day period in 2003.
The Bush administration has faced heated criticism from human rights groups for detaining prisoners for years at Guantanamo without giving them the right to defend themselves in court.
Mr Hamdan's case will be an important test of the military commission system. Of the 260 detainees currently in Guantanamo, only around 20 have been charged with a crime and the government plans to put only 60 to 80 of them on trial.
Mr Hamdan has been described by US journalists who attended his hearings at Guantanamo as haggard, with difficulty walking due to back pain.