Appeals judges at the international war crimes tribunal in the Hague have doubled the sentence of a former Bosnian Serb prison commander to 15 years.
Krnojelac (left) was initially sentenced last year
The man, Milorad Krnojelac, had earlier been sentenced to seven-and-a-half years' imprisonment for the inhumane treatment of prisoners but was acquitted of charges of murder and torture.
Judges in The Hague said the trial court had not taken sufficient account of his role in running the prison. On Wednesday they found him guilty of the crimes, and expanded his criminal responsibility, convicting him of persecution, forced labour, deportations and expulsions.
During the Bosnian war Krnojelac had been a warden at the Foca camp which was used to detain more than 700 non-Serbs after the area was captured by Serb forces at the beginning of the 1992-95 conflict.
Prosecutors say people held at the camp were subjected to starvation, assaults and forced labour.
At least 26 detainees died as a result of abuse while Krnojelac was in charge - some of them beaten to death.
The BBC's Geraldine Coughlan in The Hague said Krnojelac looked shocked when he heard the appeal judges' ruling on Wednesday.
The court said that Krnojelac had the power to prevent beatings and to investigate torture by his subordinates.
It overruled the trial court on four of eight counts of persecution, murder and deportation on the basis of race or religion on which Krnojelac was originally acquitted.
"Being aware of the beatings and the suspicious
disappearances and having seen the bullet impacts in the walls,
Krnojelac was in a position to reflect that the perpetrators of
these beatings were likely to have committed murder," the judges said.
Krnojelac, a former maths teacher and Yugoslav army captain,
was commander of the prison from April 1992 to August 1993.
He was captured by Nato-led peacekeepers in June 1998 and held in custody until his original sentencing in March last year.
On Tuesday, judges entered a plea of not guilty for Mitar Rasevic, the guard commander at Foca. He surrendered to the court last month.