A US military judge on Thursday allowed a federal agent to testify in the trial of Osama bin Laden's former driver, despite objections from defence attorneys who argued the information was obtained under coercion, dpa reported.
In his testimony, Robert McFadden, who as an agent with the Naval Criminal Investigative Service interrogated Salim Hamdan in 2003, told jurors that Hamdan admitted he had sworn allegiance to bin Laden and al-Qaeda, the Miami Herald reported.
Hamdan's trial in Guantanamo Bay, Cuba entered its ninth day on Thursday and prosecutors were close to wrapping up their case. Hamdan faces life imprisonment if convicted of conspiracy and providing material support for terrorism.
"He said he pledged 'bayat' to Osama bin Laden," McFadden said, using the term for an Islamic oath.
Hamdan, 37, of Yemen, denied taking the pledge and says the information was provided while he was abused and sexually humiliated.
The judge, Captain Keith Allred, opened Thursday by saying he had reversed his provisional ruling that the interrogation took place under "coercive measures."
Hamdan's trial is the first under the military commission established by President George W Bush for trying suspects in the war on terrorism who are being held at Guantanamo.
The Pentagon has charged 20 detainees, and that number is expected to climb to 80 of the 270 prisoners remaining at Guantanamo.
The trial of the alleged mastermind of the September 11, 2001, terrorist attacks, Khalid Sheikh Mohammed, and four other defendants in the death penalty cases could get under way as early as September. Mohammed declared during a hearing in June that he wanted to be martyred.