A German-Syrian businessman suspected of funding al-Qaeda and who had been fighting extradition to Spain has been freed by Germany's highest court.
The Federal Constitutional Court ruled against a type of arrest warrant designed to speed up extradition between European Union states.
The German government has described the ruling in the case of 46-year-old Mamoun Darkazanli as a setback against terrorism.
The European Commission urged Berlin to address the problems and try again to implement the EU arrest warrant in full.
Mr Darkazanli has been in custody in Hamburg since last October and has denied any involvement in terrorist activity.
He has been accused by the US of financing al-Qaeda and was investigated by German authorities for links to the Hamburg cell that led the 11 September attacks in the US. He has not been charged in Germany.
The businessman was one of 35 people charged by Spanish Judge Baltasar Garzon in September 2003 with belonging to al-Qaeda.
