Mr Moreno-Ocampo said he "thanked the government for the invitation" to make the visit, after meeting Prime Minister Guillaume Soro on his arrival.

BBC: ICC prosecutor arrives in Ivory Coast to probe abuses

Mr Moreno-Ocampo said the ICC had learnt "through informal channels" that mercenaries were offering to move Saif al-Islam to a country that has not signed up to the ICC's Rome statute.

BBC: Libya: Gaddafi son Saif al-Islam says he is innocent

"According to the rules, Libya has the primacy to prosecute Saif, so if they present this to the International Criminal Court judges, probably they will get an approval, " Moreno-Ocampo said on Thursday.

CNN: Hand over Saif Gadhafi, court tells Libya

In requesting the new warrant in May, Chief Prosecutor Luis Moreno-Ocampo said he was seeking to expand the charges after reviewing evidence in the case against Thomas Lubanga, a former Congolese militia leader.

CNN: STORY HIGHLIGHTS

The lives of Mrs Ocampo and another prosecution witness are said to have been threatened.

ECONOMIST: Philippines

The African Union, never a friend of the ICC, said Mr Moreno-Ocampo was egotistical and prejudiced against Africa.

ECONOMIST: The ICC and Africa: Dim prospects | The

As Mr Moreno-Ocampo arrived in Libya, Libya's Justice Minister Mohammed al-Allagui said: "In a nutshell, we are not going to hand him over, " reported the AFP news agency.

BBC: Libya's interim PM unveils new government line-up