ZAGREB, Croatia — A Croatian court on Friday annulled a 1946 verdict against a Catholic cardinal who had been convicted by the former communist authorities of collaborating with the pro-Nazi puppet regime during World War II.

The Zagreb Country Court Friday overturned the treason conviction against Cardinal Alojzije Stepinac, who was sentenced to 16 years in prison and forced labor, the official HINA news agency reported.

Judge Ivan Trudic ruled that the post-WWII verdict “gravely violated” basic legal rules, including the right to a fair trial, HINA said. Trudic described the proceedings as a “staged political process.”

Stepinac is considered a hero by many Croats but is accused by Serbs and Jews of sympathizing with the Ustasha authorities that orchestrated the killings of tens of thousands in Croatian concentration camps.

Friday’s ruling likely will fuel tensions in relations with neighboring Serbia, which considers Stepinac to be a war criminal. The Serbian Orthodox Church has protested a bid by the Catholic Church to declare Stepinac a saint.

Croatia, a staunchly Catholic country, became part of the communist-run Yugoslav federation after WWII. Yugoslavia broke up in a series of ethnic conflicts in the 1990s pitting its former republics against each other.

Croatia joined the European Union in 2013.