Muammar Gaddafi's son Saif al-Islam appeared in a court on Thursday for the first time since his capture more than a year ago, Libya's public prosecutor's office said.
The son of the former Libyan leader was in court in the western town of Zintan, where he is being held by former rebels, to face charges related to a visit by an International Criminal Court (ICC) lawyer last year.
"He is charged with involvement with the ICC delegation which is accused of carrying papers and other things related to the security of the Libyan state," Taha Baara, spokesman for the prosecutor, told Reuters.
The ICC lawyer, Australian Melinda Taylor, was herself arrested and held for three weeks after the meeting and has since said her detention proved that Saif al-Islam could not receive a fair trial for war crimes and instead should be tried in The Hague.
Another ICC defense lawyer said the court hearing in Zintan - part of Libya where the Tripoli authorities have little sway - was designed to intimidate the international court.
"This is yet another disgraceful attempt by Libya to manipulate and intimidate the ICC," said Ben Emmerson, lawyer for Abdullah al-Senussi, Gadaffi's former spy chief and Saif al-Islam's co-accused.
"It is proof positive of the urgent and imperative need for the (U.N.) Security Council to impose sanctions on Libya for its flagrant, deliberate and grave violations of Security Council resolution 1970."
That resolution obliges Libya to cooperate with the court, lawyers say, and Tripoli's failure to hand over Saif al-Islam could result in it being reported to the Council.
Libya wants to prosecute him at home, where he might face the death penalty, rather than hand him to the ICC where he could only receive a jail sentence.
An ICC spokesperson said the court was not aware of the proceedings and declined to comment.
Libyan spokesman Baara said the Zintan tribunal would convene again on May 2.
"Investigations for trying him for war crimes are over and he will be put on trial for that at a later time," Baara told Reuters.
Libya has hired human rights lawyers to argue before ICC judges that it has the ability to give the pair a fair trial and should be allowed to do so.
It is up to the ICC to decide if this is the case, and Libya has pledged to abide by the ICC's decision, most recently stressing in a Tuesday filing that it had no immediate plans to proceed with a trial of the two men.
(Additional reporting by Thomas Escritt in Amsterdam; Writing by Mahmoud Habboush; Editing by Robin Pomeroy)