Germany's Constitutional Court issued a ruling on Friday prohibiting the extradition of a known left-wing activist for trial in Hungary - but the decision came too late.
The person concerned had been handed over to the Hungarian authorities just under an hour earlier, according to a statement from the court in Karlsruhe.
The much-debated case concerns a 23-year-old born in central German city of Jena who is known in left-wing circles only as "Maja," and identifies as non-binary.
According to the Constitutional Court, the Hungarian authorities accuse Maja of being a member of a criminal organization whose aim was to attack followers of the extreme right.
Maja was detained in Berlin in December 2023, according to defence lawyer Sven Richwin, and was held in custody in Dresden in connection with violent attacks on suspected right-wing extremists in Budapest in February last year.
Hungary later filed an extradition request.
Late on Thursday afternoon, a Berlin court ruled in favour of the extradition request.
Maja's lawyer then filed an urgent application to the Constitutional Court to stop the extradition.
This was received by the court at 7:38 am (0538 GMT) on Friday, according to court documents.
The judges prohibited the extradition in a ruling issued at 10:50 am. However, according to the public prosecutor's office, "Maja" had already been handed over to the Hungarian authorities.