Germany's highest court of appeals has overturned the acquittal of a man tried on charges of accessory to murder in connection with the September 11 U.S. terrorist attacks.

The court Thursday said Mounir el-Motassadeq, a Moroccan friend of the September 11 hijackers, is indeed guilty of the charge and must return to court to receive a new sentence.

German Court Overturns Acquittal of Man Charged in Connection with 9/11 Attacks

He now faces up to 15 years in prison. Last year, Motassadeq received a seven-year term for membership in a terrorist organization, but a court ordered him freed in February pending appeals.

German Court Overturns Acquittal of Man Charged in Connection with 9/11 Attacks

A German court convicted Motassadeq in 2003 of membership in a terrorist organization and of being an accessory to murder. However, an appeals court later threw out that verdict, noting that the U.S. government had withheld information relative to his defense.

German Court Overturns Acquittal of Man Charged in Connection with 9/11 Attacks

A court later acquitted him of the accessory-to-murder charge.

Motassadeq was accused of providing logistical help to the Hamburg-based terrorist cell involved in the September 11 attacks.

Motassadeq will return to a court in Hamburg to face sentencing on the accessory-to-murder charge.