Greece's Supreme Court on Thursday rejected an extradition request for eight Turkish servicemen who fled their country by helicopter after a coup attempt.

Presiding judge Giorgos Sakkas, reading out the decision, said the servicemen were unlikely to face a fair trial if returned to Turkey.

The eight officers fought extradition in a six-month legal battle, arguing that they face mistreatment in prison if returned.

Justice Minister Stavros Kontonis earlier this week had said he would respect the court decision and not make use of executive powers in the extradition case.

Lower courts issued mixed decisions on the return of the officers in a series of separate hearings.

The extradition case has further complicated ties between neighbors and NATO allies Greece and Turkey, which remain at odds over war-divided Cyprus and boundaries in the Aegean Sea.

Hours ahead of Thursday's decision, Turkish Foreign Ministry spokesman Huseyin Muftuoglu said he expected the servicemen to be returned.

"Our greatest expectation is for the coup plotters to be delivered to the Turkish judicial (authorities). We shall be following the results of this case," he said. "These coup plotters should not go unpunished."