Saif al-Islam Gaddafi, the son of Muammar Gaddafi, the late Libyan leader, has appeared via videolink at a court in Tripoli, the capital.
Saif al-Islam and dozens of former officials are facing charges ranging from corruption to war crimes, resulting from their alleged role in suppressing the 2011 uprising.
The defence team on Sunday demanded access to all the evidence against Saif al-Islam and his fellow defendants.
The case is one of the biggest in Libya's history with more than 200 witnesses and more than 40,000 pages of evidence.
Libya's ex-intelligence chief Abdullah Senussi also appeared in court on Sunday, accused of abuses during uprising.
It was the first hearing he has attended with the four lawyers picked by his family.
The former spy chief had previously appeared without legal representation, but had been told to pick a defence team or the court would choose one for him.
Saif al-Islam's trial was adjourned to May 25. He is being held in a prison cell in the town of Zintan, 170km southwest of Tripoli.
The former rebel groups holding him have refused to hand him over to the central government in Tripoli.
Al Jazeera's Omar Al Saleh, reporting from Tripoli, said the groups think the central government in Tripoli is weak and would not be able to protect Saif al-Islam from Western intelligence agencies, who they say he has incriminating evidence against.
Saif al-Islam was captured in Zintan in November, 2011, as he was fleeing to neighbouring Niger after rebel forces took Tripoli.
His brother, Saadi, was extradited from Niger in March, after he fled Libya following the collapse of the Gaddafi-government.
Saif al-Islam and Senussi are wanted by the International Criminal Court on charges of war crimes and crimes against humanity.