In 1943, Jurak was among those invited by the International Committee of the Red Cross to take part in an investigation into the massacre of ethnic Ukrainians at Vinnytsia in the 1930s. This investigation concluded that the Soviet Union had been responsible for the massacre. He also commented on the Soviet responsibility for the Katyn massacre. His article about it was published in the Zagreb newspaper run by the Independent State of Croatia. When World War II in Yugoslavia ended, OZNA had Jurak killed by firing squad in Zagreb in June 1945.