The witness described how he came into conflict with the rebel Serb authorities over the evacuation of Croatian POWs after the fall of Vukovar to the besieging JNA and Serb paramilitary forces in November 1991.
Threatening to use force, Vujic, who at that time served as a JNA security officer, took several dozen Croatian POWs from the hands of Serb paramilitaries and evacuated them to a detention camp in Srijemska Mitrovica in Serbia.
The rebel Serb authorities, headed by Goran Hadzic, did not like what Vujic had done. "They wanted me to bring them back, insisting they were Ustashas and war criminals they were going to put on trial," he said.
The witness said that one of the accused, Mile Mrksic, was aware of the intention of the Serb forces to take the wounded Croatian soldiers and civilians from the Vukovar hospital to the Ovcara farm outside the town and execute them there.
"When an officer told him that, he fell silent and raised his hand in front of his eyes meaning to say that members of the Serb Territorial Defence should be condoned," Vujic said.
Vujic said he wanted to carry out his task in accordance with the provisions of international laws of war and humanitarian law, which included a possible trial for any crimes committed by the Croatian forces in accordance with the existing federal laws.
Former JNA officers Mile Mrksic, Veselin Sljivancanin and Miroslav Radic, also known as the Vukovar Three, are held responsible for the massacre of at least 264 wounded Croatian soldiers and civilians on the Ovcara farm on 20 November 1991.
The witness will be cross-examined by defence counsel on Monday.