Jan 9, 2007
The court in Hamburg handed the maximum sentence against Mounir al-Motassadek.
He had acknowledged that he was close to the 9/11 hijackers but insisted he knew nothing of their plans.
But last year Germany's top appeals court found him guilty of abetting the murder of 246 people on the four planes that crashed on 11 September 2001.
The ruling superseded a seven-year sentence handed to Motassadek in 2005 for being a member of a terror group.
Motassadek was originally jailed for 15 years in 2003, convicted of helping the 11 September plotters, who were based in Hamburg, with logistical support and other aid.
That verdict was overturned by Germany's Supreme Court in 2004 and a retrial ordered.
The court ruled last August there was no proof that Motassadek knew about the 11 September plot and jailed him instead for membership of a terrorist organisation.
He again appealed, and was found guilty of being an accessory to murder in the attacks.