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, provided there is a judicial process that does not shield him from international justice.

Luis Moreno-Ocampo said on Wednesday at a news conference in Tripoli, the capital, that it was very important for Libya that Saif al-Islam, the captured son of the late Libyan leader, is tried inside the country.

Moreno-Ocampo arrived in Libya on Tuesday for talks with Libya's new leaders about their plans for Saif al-Islam, who was captured on Saturday in southern Libya and is being held by fighters in the mountain town of Zintan, southwest of the Tripoli.

The ICC prosecutor told Reuters news agency he believed Gaddafi's former intelligence chief Abdullah al-Senussi had not been captured.

Officials from Libya's National Transitional Council (NTC) said on Sunday that Senussi had been detained the day after Saif al-Islam was caught, and in the same southern desert region.

Libya's prime minister-designate, Abdurrahim El-Keib, later cast doubt on the reports, and the NTC has since neither confirmed nor denied Senussi's capture, though a military commander has stood by his report of the arrest.

"I understand he (Senussi) has not been arrested," Moreno-Ocampo told Reuters in an interview in Tripoli.

In a statement before his arrival, Moreno-Ocampo called the arrest of Saif al-Islam and al-Senussi "a crucial step in bringing to justice those most responsible for crimes committed in Libya".

"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."

Earlier this year, the ICC issued a warrant for Saif al-Islam's arrest on charges of crimes against humanity.

The International Committee of the Red Cross (ICRC), which visited Saif al-Islam in Zintan on Tuesday, 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.

Meanwhile, Libya's National Transitional Council named a new cabinet on Tuesday, making several unexpected appointments that suggested the line-up was meant to calm rivalries between regional factions.

Source: Agencies