The United Nations Security Council has voted to remove Carla Del Ponte from her role as the chief prosecutor for the Rwanda genocide court.
Del Ponte has led prosecutions at the court in Arusha since 1999
She has been chief prosecutor for both the Balkans war crimes tribunal and the Rwanda court for four years, but the council has decided to split the two posts, which they consider too much work for one person.
Ms Del Ponte will retain her Balkans position when her initial term of office expires on 14 September, and a new prosecutor, to be nominated by UN Secretary General Kofi Annan, will take charge of cases stemming from the 1994 Rwanda genocide.
The former Swiss attorney general had argued against the split, complaining to the Security Council that she was a victim of undue political pressure from Rwanda, and saying that international justice could be damaged if her duties were shifted.
The tribunal was set up to investigate the massacre of some 800,000 ethnic Tutsis and moderate Hutus by Hutu extremists in 1994.
Ms Del Ponte accused the current government of seeking her removal after she tried also to investigate claims that members of the Tutsi-dominated army killed up to 30,000 Hutus, as it took control of Rwanda in the wake of the genocide.
The Rwandan Government has lobbied hard to have its own prosecutor, but insists it is not responsible for Ms Del Ponte's removal.
Rwandans have long argued the International Criminal Tribunal in Arusha, Tanzania, has been plagued by mismanagement and a lack of attention from successive prosecutors.
Gerald Gahima, Rwanda's Prosecutor General, said people took "strong exception" to the fact that the investigation of almost one million deaths has been made a "part-time job of a prosecutor based on another continent".
Diplomats say that they expect the role to now go to an African.
Mr Annan himself recommended that the jobs be separated.
The UN resolution, sponsored by the United States, which the council voted unanimously to support, said the council was convinced that the tribunals "can most efficiently and expeditiously meet their respective responsibilities if each has its own prosecutor".
The new resolution also sets out the timetable for completing the work of both the Rwandan and Balkans tribunals by 2010.
It urges both tribunals to focus on rounding up and prosecuting leaders and allowing cases involving lower ranking suspects to be transferred to national courts instead.