The Yugoslav war crimes court was Thursday to rule in an appeal brought by two former top Bosnian Serb officials against their conviction and 22-year jail term for their roles in the brutal 1990s war.
Mico Stanisic and Stojan Zupljanin were sentenced in 2013 after being convicted of a campaign to rid Bosnia of Muslims, Croats and other non-Serbs during the 1992-1995 conflict.
The two men were close associates of one-time Bosnian Serb leader Radovan Karadzic, who was found guilty in March on charges of genocide and war crimes for his role in the fighting that killed more than 100,000 people and left 2.2 million others homeless.
"With a few hours to go before the delivery of the judgement, Mr Stanisic is very nervous," his defence lawyer Stephane Bourgon told AFP Thursday.
Stanisic, 62, a former Bosnian Serb interior minister, and ex-regional security services chief Zupljanin, 64, were convicted of 10 charges of war crimes and crimes against humanity including murder and torture.
They were also accused of the cruel treatment of non-Serbs in municipalities and detention centres during the war triggered by the break-up of the former Yugoslavia after the fall of communism.
The prosecution at the International Criminal Tribunal for the former Yugoslavia (ICTY) has also appealed the sentence as too light "for the seriousness of the crimes."
Based in The Hague, the ICTY found in March 2013 that the two men took part in a joint criminal enterprise known as ethnic-cleansing to remove non-Serbs from Bosnia's municipalities marked to become part of the Serbian state.
They were found to have allowed forces under their command to engage in the "violent takeover of those municipalities and the ensuing widespread and systematic campaign of terror and violence."
The crimes were committed between April and December 1992 in 20 of Bosnia's municipalities and 50 different detention facilities set up by Bosnian Serb forces where captives were beaten, tortured, mutilated, sexually assaulted, humiliated and physically abused.
- Claims of bias -
Defence lawyers opened an appeal against the conviction and prison sentence in December 2015, with Stanisic's lawyer Bourgon accusing the judges of bias during the three-and-a-half year trial.
Bourgon based his argument on a bombshell letter written by Danish former ICTY judge Frederik Harhoff in mid-2013 in which the judge harshly criticised a sudden raft of acquittals before the court.
In the letter, Harhoff claimed the tribunal's then president, US judge Theodor Meron, had leaned on other judges to acquit defendants, suggesting possible pressure from the United States and Israel.
Harhoff was one of the three-judge bench that sentenced Stanisic and Zupljanin, and the defence argued the judge's letter showed he was "on a mission to convict" the accused.
Bourgon told AFP Thursday he believed the defence had "raised solid grounds of appeal, both on the substance of the case as well as in relation to the issue concerning former Judge Harhoff."
"We take the view that in this case, former Judge Harhoff ventured beyond the conduct that is acceptable on the part of a judge."
The prosecution has however argued the two men were sentenced by a unanimous bench which based their verdict on strong evidence.
Meanwhile the defence team has advised Stanisic "not to have any expectations, simply because we know that anything can happen."
The two men have been held in a special Dutch detention unit in the Hague suburb of Scheveningen. Stanisic had a visit from his family just over a month ago.
