Moroccan Mounir El Motassadeq received a seven-year jail sentence today after being found guilty in a German court of belonging to a terrorist group.
Judge Ernst-Rainer Schudt told the court that Motassadeq (31) had been found not guilty on a separate charge of being an accessory to the September 11th attacks on the United States.
The verdict came after a year-long retrial at which prosecutors had tried to prove Motassadeq helped plot the suicide hijack attacks that killed nearly 3,000 people in 2001.
He had been convicted on both charges at a first trial in 2003, but that ruling was quashed on appeal. The prosecution had been asking for a 15-year sentence for Motassedeq.
The outcome hinged largely on evidence from captured al-Qaeda prisoners, which the US government withheld from Motassadeq's first trial and made available only in limited form at the retrial.
Washington declined, on security grounds, to let the court question the prisoners, including two senior figures being interrogated at secret locations on suspicion of masterminding the attacks. It released only summaries of information they revealed under questioning.
One of them, Ramzi bin al-Shaibah, said Motassadeq was one of a group of Arab students in Hamburg who had "studied jihad" (holy war) and "engaged in vitriolic anti-US discussions" at the home of Mohamed Atta, the man who crashed the first hijacked plane into New York's World Trade Center.
But he said he knew nothing of the plot.