The International Criminal Court Wednesday said it had "exclusive competence" over the prosecution of deposed leader Moamer Kadhafi's son Seif al-Islam, after its chief prosecutor said Libya had priority in the case.
The June 2011 warrant issued by the court for Seif on charges of crimes against humanity remain "outstanding and procedures as provided for in the Rome Statute need to be followed," the court said in a statement.
"The pre-trial chamber judges have the exclusive competence to decide on the continuation of the ICC judicial procedure," it said.
"Should the Libyan authorities wish to conduct national prosecutions against the suspect, they shall submit a challenge to the admissibility of the case" to the ICC, it said.
"Any decision on the admissibility of a case is under the sole competence of the judges of the ICC," it said.
"Therefore, contrary to what has been reported in the media, pre-trial chamber I of the ICC remains seized of the case and the Libyan obligation to fully cooperate with the court remains in force."
Earlier on Wednesday during a visit to Tripoli, ICC chief prosecutor Luis Moreno-Ocampo said Libya had every right to try Seif al-Islam, arrested last week, and that the court could even provide Libya with the fruits of its investigation so far.
"The primacy is for the national system. If they want to do it, we are not competing with them," Moreno-Ocampo said at a media conference.
"We do it when they can not do it," Moreno-Ocampo said. "As soon they can do it, we stop. This is the system, and it's what we are discussing here."
During the news conference, Moreno-Ocampo said as long as Libya conducted appropriate investigations and presented its findings to ICC judges "the rules say they can do it."
"We are not doing something else."
Libya's Interim Justice Minister Mohammed al-Allagui said talks toward a cooperation deal between the ICC and the new government in Tripoli were under way while maintaining that "all the guarantees and conditions are available in Libya for a fair trial."
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"It is the will of the Libyan people," Allagui said, stressing that trying Seif in Libya was not contradictory to cooperating with the ICC.
Moreno-Ocampo later said that Tripoli authorities had invited the ICC to continue its investigation.
"They (would) like us keeping doing the investigation for a while, to complete the investigation if we can," Moreno-Ocampo said.
"So we're discussing modalities, we are still investigating the crimes, and eventually if there's no security problem we can pass to them everything we have, because in fact today (...) they're helping us to collect the evidence," the prosecutor said.
Moreno-Ocampo is in Libya for talks on jurisdiction in the cases of Seif and Kadhafi's spymaster Abdullah al-Senussi, both of whom are wanted by the court on charges of crimes against humanity.
But Allagui told reporters the authorities could no longer confirm the arrest of Senussi, reiterating Tuesday comments by US envoy to the United Nations Susan Rice that the former spymaster and brother-in-law to Moamer Kadhafi was still missing.
National Transitional Council officials and military commanders had said Senussi was captured on Sunday at his sister's home in the southern Libyan region of Al-Guira where he had apparently been hiding.
Reports of his capture came a day after Libya's new rulers announced the arrest of Seif al-Islam to much fanfare.
Video footage showing Seif's capture has been widely publicised but there have been no pictures of Senussi following his reported arrest.
On Tuesday, the head of the military council of the southern Wadi Shati region, where Al-Guira is located, insisted in remarks to AFP that Senussi was in custody.
"According to my sources he has been arrested and is being kept in a secret place to protect his life," said Bashir Uweidat.
Senussi was in the southern Sabha region, he said, without providing further details.