Turkey's President Recep Tayyip Erdogan has accused Germany of "abetting terrorists" amid a widening spat between Ankara and Berlin, CNN reported.

Speaking at a conference in the Black Sea province of Rize, Erdogan said Turkey had given German Chancellor Angela Merkel "4,500 dossiers but have not received an answer on a single one of them."

"When there is a terrorist, they can tell us to give that person back. You won't send the ones you have to us, but can ask us for yours. So you have a judiciary, but we don't in Turkey?" he said, according to the source.

To remind, relations between Germany and Turkey have deteriorated in recent months after Merkel questioned Turkey's commitment to democracy and the rule of law, while Erdogan suggested Germany's Nazi past might not be entirely behind it.

Berlin has also so far refused to extradite soldiers and civilians Ankara accuses of being among the higher level coordinators of last year's attempted coup.