An autopsy revealed that the 78-year-old priest was killed on February 8 and police suspect the murder was committed by a number of people.
The media reported that the priest was first stabbed in the neck and then had his head smashed with a rock.
Police have still said nothing about the motive but it is assumed Ivancic was murdered for gain.
Since the priest also had Croatian citizenship, the Croatian ambassador to Bosnia discussed the case with Security Minister Radoncic, who said all security structures and law enforcement agencies were undertaking the necessary measures to bring the perpetrators to justice.