The International Criminal Court's prosecutor has urged Muammar Gaddafi's own aides to turn him over for trial on murder charges - or risk prosecution themselves.

As battles raged through a fifth month between Gaddafi's forces and rebels backed by Nato air strikes, prosecutor Luis Moreno-Ocampo was optimistic that Gaddafi's regime would be over within two or three months.

The court has issued arrest warrants for the Libyan leader, his son Saif and intelligence chief Abdullah al-Sanoussi for crimes against humanity. But the court has no police force, and relies on the law enforcement agencies of the 115 countries that ratified the court's founding statute.

Libya is not a member, but Mr Moreno-Ocampo advised Gaddafi's inner circle to arrest their leader. They "can be part of the problem and be prosecuted or they can be part of the solution - work together with other Libyans and stop the crimes," he said.

Nato forces operating in Libyan skies have no mandate to arrest suspects, he said. And Nato itself has said it does not want to put combat forces on the ground. The prosecutor said the other option for arresting Gaddafi is through the rebels fighting to end his more than four decades in power.

Mr Moreno-Ocampo insisted he will eventually be tried.

He cited the arrest last month of former Bosnian Serb military chief Ratko Mladic after 15 years on the run as an example of how internationally wanted suspects almost always end up in court.

"It's a matter of time. See what happened with Mladic," he said. "Bashir's destiny is to face justice, Gaddafi will face justice. The arrest warrants are not going away."