Saif al-Islam Gaddafi, the most prominent of slain Libyan leader Muammar Gaddafi's sons, has appeared in court in Zintan, west of the capital Tripoli, on security charges and his trial was adjourned until December, a lawyer said.
"Saif al-Islam Gaddafi appeared before the Zintan court that decided to adjourn the trial until December 12 to allow the attendance of other accused in the case," the lawyer, who was present in court, told the AFP news agency on Thursday.
He was also due at a separate pre-trial hearing in the capital on Thursday on security charges related to the 2011 uprising that toppled his father, but there were doubts whether his ex-rebel captors in Zintan would allow this.
Officials had earlier said that he may join 36 other former regime members in a pre-trial session in Tripoli over charges of murder and crimes allegedly committed during Libya's 2011 uprising.
Abdel-Qader Radwan, the prosecutor general, said that Saif al-Islam would be facing an "indictment chamber" on Thursday at Tripoli Criminal Court. Abdullah al-Senoussi, Gaddafi's former spy chief, would also appear, he said.
He said that the hearing would not be open to the public.
"This is an investigation phase, not a court session," he said.
While the Tripoli session will not mark the beginning of the trial, it will pose a crucial test for the country's fragile government.
Since the overthrow and killing of Muammar Gaddafi at the hands of rebel forces, successive interim governments have failed to impose law and order.
They instead relied on heavily armed groups, formed initially by the rebel forces, which later began challenging the central government and threatening the country's transition to democracy.
Saif al-Islam has been held by a militia group that captured him in the western mountain town of Zintan as he was fleeing to neighbouring Niger after rebel forces took Tripoli.
On the eve of the hearing rights group Amnesty International urged authorities to "immediately hand" over Saif al-Islam and Senoussi to the International Criminal Court where they are wanted on charges of crimes against humanity.
This summer, the international court judges had ruled that Libya cannot give Gaddafi's son a fair trial and asked authorities to hand him over to The Hague.
Saif al-Islam is also being tried on separate charges of harming state security, attempting to escape prison and insulting Libya's new flag.