Defense attorneys urged a German court Tuesday to throw out charges against a Moroccan man accused of helping the Sept. 11, 2001, hijackers, saying that any evidence the U.S. government gleaned from al Qaeda prisoners would be tainted by allegations of torture and abuse.

The arguments in the retrial of Mounir Motassadeq, 30, came as the court was read a U.S. government statement indicating that American officials would provide some unclassified evidence obtained from two men in secret U.S. custody but would not allow video testimony or release interrogation transcripts.

In a previous trial of the defendant, the U.S. government refused to turn over evidence from the two, Ramzi Binalshibh and Khalid Sheik Mohammad, who investigators say helped plan the hijackings. An appeals court cited that omission in overturning Motassadeq's conviction and ordering a new trial.

During Tuesday's proceedings in Hamburg, attention was focused on questions about the type and value of evidence the court would hear.

"The importance of the U.S. material and evidence for this case can hardly be overemphasized," defense attorney Josef Graessle-Muenscher told the court, according to a written version of his statement. But he argued that, in view of revelations of the mistreatment of prisoners, any evidence coming from the U.S. government would be suspect.

"Ending the trial is justified because it is no longer possible for this court to make its own evaluation of the evidence," he said. "No court can arrive at the truth . . . in this swamp of torture and the camps."

The chief federal prosecutor, Kay Nehm, emphasized to American officials on a recent trip to the United States "how urgently we need the information, especially in light of the federal court's decision" ordering the retrial, Frauke-Katrin Scheuten, Nehm's spokeswoman, said in a telephone interview last week.

The defendant is accused of membership in a terrorist organization and 3,066 counts of accessory to murder. In 2002, Motassadeq was the first person to go on trial in the German government's troubled efforts to convict people it contends are remnants of the Hamburg-based cell that led the attacks.

Another Moroccan, Abdelghani Mzoudi, was acquitted of similar charges this year.

In Motassadeq's first trial, prosecutors successfully argued that he knowingly aided the hijackers in their plot by completing tasks such as paying their bills. He acknowledged having been friendly with the hijackers but said he was unaware of their intentions and helped them only out of an obligation to fellow Muslims.

In the statement read in court, the U.S. government declined to release classified material about the prisoners on grounds that doing so would compromise sources and techniques. It claimed that allowing the court to have "interactive access" to the prisoners could hamper continuing interrogation and divulge secret information, according to news service reports.

In addition to providing unclassified information, the Americans will allow a U.S. intelligence officer to testify in court.

Moroccan Mounir Motassadeq arrives with his attorneys, Josef Graessle-Muenscher, left, and Udo Jacob, at a court in Hamburg for the first day of his retrial on charges related to the Sept. 11, 2001, attacks.