This is a strange one. It is being reported by Russian media but blanked out by the German press. Deutsche Welle made one report about it, in Russian, denying that the story was true. The Russians are saying that the girl was subjected to hostile, mocking interrogation for hours by the police and eventually broke down and agreed to state that her story was a lie. Her family claim the rape really happened and only this "psychological torture" from the police made her say otherwise.
The Russian community in Berlin have held protests about it.