The International Criminal Court (ICC) on Wednesday rejected Libya's request to postpone the surrender of Saif al-Islam Gaddafi, the most prominent son of the country's former leader, to face war crimes charges.
The Hague-based court ordered Tripoli to "comply with its obligations to enforce the warrant of arrest" and surrender him into the court's custody without delay.
It issued a warrant for Saif al-Islam in June, after prosecutors accused him and others of involvement in the killing of protesters during the revolt that eventually toppled his father, Muammar Gaddafi, in August.
But Libya has so far refused to hand him over, saying the once swaggering Gaddafi son should face justice at home.
The ICC says it has jurisdiction over the case because it issued warrants last year for the arrest of Muammar Gaddafi, Saif al-Islam, and the Libyan leader's intelligence chief, Abdullah al-Senussi who was arrested last month in Mauritania.
A U.N. Security Council Resolution obliges Libya to cooperate with the court, the ICC says, and Tripoli's failure to hand Saif al-Islam over could result in it being reported to the Council.
He faces the death penalty if found guilty by a Libyan court, but only a prison term if convicted by the ICC.
Saif al-Islam's supporters say they doubt he will be given a fair trial in Libya and would prefer him to be tried by the ICC in The Hague.
Since the elder Gaddafi was killed after being captured alive by rebel fighters, competing militias have yet to lay down their arms and Western human rights organisations have accused them of carrying out numerous extra-judicial executions and other abuses, raising questions about the rule of law there.
New York-based Human Rights Watch (HRW) also believes Saif al-Islam would receive a fairer and safer trial in the Netherlands.
"Today's decision means that ... the authorities (in Libya)must start making arrangements to surrender Saif al-Islam to the court," said Richard Dicker, HRW's international justice program director.
The ICC had earlier given Libya until Jan. 10 to confirm whether and when it would surrender Saif al-Islam and to provide information about his health. It extended the deadline until February.