Germany's top court today blocked the extradition of a suspected al-Qaeda financier to Spain after ruling a key instrument in the European Union's fight against terrorism breached the constitution.
Mamoun Darkazanli was released by Germany's Federal Constitutional Court.
The Federal Constitutional Court ordered the release of Mamoun Darkazanli, a German-Syrian who is fighting his handover under an EU arrest warrant. The court said Germany had not implemented the new warrant correctly.
In doing so, the court upheld an article of the post-war constitution preventing the state from extraditing its citizens, with only limited exceptions.
The ruling could undermine the warrant, one of the bloc's most significant security initiatives since the September 11th attacks in 2001 and introduced last year to speed up the handover of suspects and boost co-operation in the fight against terrorism.
The European Commission urged Berlin to address the problems and try again to implement the EU arrest warrant in full.
German Justice Minister Brigitte Zypries said the court's decision was a setback for the battle against international terrorism.
Ms Zypries said a new law could be ready within four to six weeks, although an expected German general election in September could stall the warrant's relaunch for months.