The International Criminal Tribunal for the Former Yugoslavia said that Dunjic died on Thursday in a hotel in The Hague and that a court official found the body, while the cause of death is being investigated.

“Emergency services personnel were immediately notified and ascertained Mr. Dunjic’s death. Dutch authorities are conducting an investigation into Mr. Dunjic’s death,” the tribunal said in a statement.

Mladic, the wartime commander of the Bosnian Serb Army, is on trial for genocide against about 7,000 Bosniaks from Srebrenica in the days that followed the occupation of the town on July 11, 1995.