Saif al-Islam, the son of deposed Libyan leader Muammar Gaddafi, has appeared briefly in court where a militia has held him since his capture in November 2011, a local council official has said.
He is wanted by the International Criminal Court (ICC) on war crimes charges, but the current case relates to charges that he gave information to an ICC lawyer last year that could endanger national security.
Saif al-Islam was the only defendant of 13 people who were called to appear in court on those charges, confirming he was in the room when his name was called out and that his lawyers were present.
The case was then postponed until September 19 because the defence's case was incomplete.
Australian Melinda Taylor, the ICC lawyer, was herself detained for three weeks after a meeting in which Saif al-Islam is accused of handing over sensitive papers and information.
Taylor has said her detention proved Saif al-Islam could not get a fair trial in Libya and should be tried in The Hague.
Libya, which wants to try Saif al-Islam itself, has yet to indict him for war crimes, although the public prosecutor has said a case is being prepared and will soon go to court.
The defendant smiled and told journalists he was in good health during his appearance, seated behind a grille and with two masked policemen at his sides.