The chief prosecutor for the International Criminal Court has said there are "serious suspicions" that the death of Libyan leader Muammar Gaddafi was a war crime.
Luis Moreno Ocampo has sent a letter to the head of Libya's National Transitional Council asking about the new government's plans to investigate alleged war crimes by all parties, including the rebels.
Witness accounts and video taken of the deposed dictator after his capture by rebel fighters show that he was beaten and abused, and there were strong indications that he was killed in custody.
"The death of Muammar Gaddafi is one of the issues to be clarified because there are serious suspicions that it was a war crime," Mr Moreno Ocampo said.
He said what the ICC does on Gaddafi's death and other war crimes will depend on what Libya's interim government does because under the Rome statute that established the war crimes tribunal, the ICC only steps in if national authorities are unwilling or unable to act.
Mr Moreno Ocampo's office is also working with Libyan authorities on the case of Gaddafi's son, Saif al-Islam, and former intelligence chief, Abdullah al-Senoussi.
Libya's new leaders are keen to try al-Islam at home, despite not yet having a strong court system.