Polish prosecutors have opened an investigation into the head of the country's Constitutional Tribunal to determine if he abused his power in not allowing judges appointed by the ruling party to take part in rulings.
 
The investigation into Andrzej Rzeplinski, which opened Thursday, is the latest development in an ongoing conflict between the Polish government and the constitutional court, whose role is similar to the U.S. Supreme Court.

The government's conflict with the court has raised international concerns about the state of democracy in Poland, and the political opposition and other critics have slammed the investigation into Rzeplinski as an attack on the separation of powers.

Amid the conflict, Rzeplinski has emerged as one of the key symbols of resistance against the right-wing government, which has moved to centralize power since winning elections last year. The investigation is seen by many as an attempt to discredit him since he enjoys, at least for now, immunity from prosecution. His term as head of the court also expires in December.