Serbia has deliberately failed to bring fugitives Radovan Karadzic and Ratko Mladic to justice, the UN's outgoing chief war crimes prosecutor has said.
Radovan Karadzic (left) and Gen Ratko Mladic remain on the run
Their liberty "undermines the very idea of international justice," Carla Del Ponte told the United Nations Security Council in a final speech.
Ms Del Ponte addressed the council at the end of eight years as prosecutor.
She pledged from the start to see justice done, but seems set to leave office on 31 December disappointed.
Between them Radovan Karadzic and Ratko Mladic face 16 counts of genocide, crimes against humanity and violation of the laws of war in Bosnia-Herzegovina between April 1992 and July 1995.
They were charged and indicted by the UN war crimes tribunal at The Hague in 2005, but both remain at large.
Ms Del Ponte said that despite Serbian promises to co-operate with her, "there is no clear road map, no clear plan in the search for fugitives, no serious leads and no sign that serious efforts have been taken to arrest the fugitives".
She said Serbian authorities "chose not to arrest" Gen Mladic in early 2006 although they "knew his exact whereabouts", while Mr Karadzic was known to have spent time in Belgrade, using his own name, as recently as 2004.
She called the failure a "stain on the international tribunal's work".
Ms Del Ponte said she was leaving "this unfinished business" to her successor, Belgian prosecutor Serge Brammertz.
Serbia's UN envoy praised Ms Del Ponte's "determination"
But she urged EU member states to deny Belgrade's ambitions for membership of the European Union until it co-operated fully with the tribunal.
In response, Serbia's UN envoy Pavle Jevremovic expressed appreciation for Ms Del Ponte's "commitment and determination", and said he believed remaining fugitives would be caught "in the nearest future".
Ms Del Ponte's comments come despite the fact that only four of 161 people originally indicted by the tribunal remain at large.
But Ms Del Ponte had made the capture of the "Big Three" - Karadzic, Mladic and former Yugoslav leader Slobodan Milosevic - her personal mission.
She was reported to have hung their portraits behind her desk when she took up her post.
Milosevic died while on trial at The Hague, while the other two men have both slipped from the prosecutor's grasp.