A court in Hamburg has been told that a Moroccan, who is being retried in connection with the 11 September attacks, had no knowledge of the plans.
The US Department of Justice provided the court with summaries from interrogations of two al-Qaeda suspects in American custody, saying that Mounir el-Motassadeq was not part of the group's inner circle.
The 30-year-old was sentenced to 15 years in prison last year, but in March a federal German court ordered a retrial after a potentially crucial witness who was in US custody was kept from testifying.
Yesterday, the German judges revealed that the US would not allow them to question al-Qaeda prisoners during the retrial.
Before Mr Motassadeq's conviction was quashed, he was the only person to have been found guilty of taking part in the attacks in 2001.
He is charged with complicity in the murder of about 2,800 people and membership of a terrorist organisation.
