Appeals judges in the Hague have upheld the war crimes conviction of former Liberian President Charles Taylor.

They reaffirmed the 50-year prison sentence he was given last year for war crimes and crimes against humanity committed during Sierra Leone's civil war.

Taylor, 65, sat impassively throughout the reading of the appeals judgment at the UN-backed Special Court for Sierra Leone in The Hague.

He is the first head of state to be convicted of war crimes by an international court since the Nuremberg trials of Nazi leaders after World War II.

Taylor was also found guilty of crimes against humanity committed during the 11-year conflict in Sierra Leone, which killed some 50,000 people and left tens of thousands mutilated, with their fingers, hands or limbs chopped off.

Prosecutors said he used the proceeds from "blood diamonds" mined in the conflict zone to finance his activities, which included advising and helping the rebels.

Presiding Judge George Gelaga King said Taylor had aided and abetted crimes committed by Revolutionary United Front and Armed Forces Revolutionary Council rebels, advising and assisting them while knowing well the kinds of crimes they were committing.