"Binalshibh, who was captured last week in Pakistan, has been handed over to U.S. authorities and moved out of that country. He is to be taken to an undisclosed third country for further interrogation, officials said… This official would not disclose the location or even the country where Binalshibh is being held, and said U.S. investigators are not pressing for Binalshibh to be brought to the United States at the moment."

In May, German authorities asked the United States to provide access to six key witnesses, including Ramzi Binalshibh, a Yemeni who is believed to have been the Hamburg al Qaeda cell’s key contact with Osama bin Laden’s organization.

However, in its letter, the United States said that even information on whether a given individual was in custody was classified as secret.

Other key witnesses sought by German authorities include suspected September 11 plotter Zacarias Moussaoui and Khalid Shaikh Mohammed, who is thought to be the mastermind of the attacks.

Opening the retrial Tuesday, Judge Schudt said the Hamburg state court wouldn’t be swayed by political pressure.

"For me, this is not about fulfilling the expectations of governments or the public," he said. "The black hole in the chain of evidence will close. We will certainly not sink into it."

El Motassadeq smiled but said nothing as he entered the court. He briefly answered questions about his identity but turned down the judge’s offer to respond to the indictment, AP reported.

El Motassadeq’s lawyer said he would maintain his client’s innocence, then ask the court to drop the proceedings because past experience showed el Motassadeq would not get a fair trial.

Lawyer Josef Graessle-Muenscher told AP he would argue that torture "underlies the interrogation system of the United States," making any evidence from Binalshibh or Mohammed inadmissible even if it is provided.

He cited reports from prisoners released from U.S. military detention at Guantanamo Bay, Cuba, and the policy of holding Taliban and al Qaeda suspects without giving them the usual rights of prisoners of war set out in the Geneva Conventions, AP said.

El Motassadeq is accused of helping pay tuition and other bills for members of the Hamburg al Qaeda cell, which included suicide hijackers Mohamed Atta, Marwan al-Shehhi and Ziad Jarrah, to allow them to live as students as they plotted the attacks.

He admitted training in bin Laden’s camps in Afghanistan, and witnesses at his trial testified that he was as radical as the rest of the group, often talking of jihad — holy war — and his hatred of Israel and the United States.

He signed Atta’s will and had power of attorney over al-Shehhi’s bank account.

El Motassadeq has said he was nothing more than close friends with the others and did only things that a good Muslim would do for any "brother."