The International Criminal Court's chief prosecutor has accepted that Muammar Gaddafi's son Saif al-Islam will be tried in Libya.
Luis Moreno-Ocampo has arrived in Tripoli following the capture of Colonel Gaddafi's eldest son.
The International Criminal Court had been seeking him on charges of crimes against humanity, including the murder and persecution of civilians.
Mr Ocampo says the ICC requested the arrest warrant in May because it felt Libyans could not bring Saif al-Islam to justice, the BBC reports.
He says that is no longer the case and Libya is free to put him on trial itself, rather than the trial taking place in The Hague.
"Saif is captured, so we are here to ensure co-operation," he says.
Mr Ocampo says the ICC will help Libya to bring Saif al-Islam to justice.