The International Criminal Court's prosecutor has said that Libya can put Muammar Gaddafi's son and one-time heir apparent on trial at home, but that its judges must be involved in the case.
Luis Moreno-Ocampo was in Tripoli on Tuesday for talks with Libya's new leaders about their plans for Saif al-Islam Gaddafi, who was captured on Saturday in southern Libya and is being held by fighters in the mountain town of Zintan, southwest of the Libyan capital.
"Saif is captured so we are here to ensure co-operation," Moreno-Ocampo said. "If they [Libyans] prosecute the case, we will discuss with them how to inform the judges, and they can do it, but our judges have to be involved."
The Hague-based ICC has charged Saif al-Islam with crimes against humanity.
Moreno-Ocampo's remarks came just hours before Libya's interim prime minister, Abdurrahim El Keib, announced the formation of a transitional government that will lead the country until parliamentary elections are held by the end of June.
Since toppling Gaddafi in August, Libya's new leaders have been struggling to solidify their control over the fractured nation and to begin building state institutions that were nonexistent or weak under Gaddafi.
Among the most important is establishing a court system, which the Hague-based ICC wants to be certain will be capable of putting on a fair trial for Saif al-Islam.
'In good health'
Tuesday's developments came as the International Committee of the Red Cross said it had visited Saif al-Islam in Zintan and said he appeared to be in good health.
Steven Anderson, a spokesperson for the Geneva-based body, said the visit "took place in accordance with the ICRC's customary working procedures" and all further findings would remain confidential.
The ICC has also charged Gaddafi's former intelligence chief, Abdullah al-Senoussi, with crimes against humanity.
Libyan officials have said al-Senoussi was captured over the weekend and is being held in the southern city of Sabha, although El Keib could not confirm the report.
Libya is obliged by a Security Council resolution to work with the ICC, but that does not necessarily preclude a trial in Libya.
If the governing National Transitional Council can convince judges in The Hague that the country has a functioning legal system that will give Saif al-Islam and al-Senoussi a fair trial on substantially the same charges as Moreno-Ocampo filed, then the ICC could declare Moreno-Ocampo's case inadmissible and turn it over to Libya.
"The International Criminal Court acts when the national system cannot do it," Moreno-Ocampo said. "That's why we are here, to understand what they are doing."
In a statement before his arrival, Moreno-Ocampo called the arrest of Saif al-Islam and al-Senoussi "a crucial step in bringing to justice those most responsible for crimes committed in Libya".
Libya's new leaders have not yet established a functioning judicial system, and have struggled to put together a new transitional government since Gaddafi's fall.