A convicted Moroccan accomplice in the September 11, 2001, attacks on the United States was expelled from Germany on Monday and sent back to Morocco, police said.
Mounir el Motassadeq was sentenced in January 2007 by a German court to 15 years in jail for his role in the death of 246 passengers and crew aboard hijacked aircraft used in the September 11 attacks.
He was the first person ever convicted for complicity in the attacks on the World Trade Center and the Pentagon.
The Moroccan was put on a plane at Frankfurt airport and sent back to his country of origin, according to an airport police spokesman, speaking to the German national news agency DPA.
Several police officers accompanied him.
Earlier he had been taken by helicopter from the Hamburg jail where he has been serving his prison term to Frankfurt, according to Spiegel Online and Bild daily.
Photographs carried by DPA showed him dressed in a checked shirt and beige trousers, being led blindfolded and handcuffed by two police officers to a waiting chopper.
Motassadeq, who was held in prison just after his arrest in late 2001, had served nearly all of his sentence.
He has admitted to having links to the hijackers, but he maintained his innocence in a five-year court battle.
The Moroccan was friends with members of a Hamburg-based cell including their leader Mohammed Atta. He helped to cover up their whereabouts while they were taking flying lessons in the United States and handled a bank transfer for them.