Saif al-Islam Gaddafi, the son of former leader Libyan Col Muammar Gaddafi, will be tried in August, the prosecutor’s office has announced.
It said the case against him and other senior regime members would include charges of forming criminal gangs, inciting rape and illegal detentions.
Prime Minister Ali Zeidan told the BBC that they would “receive a fair trial”.
Libya has resisted the International Criminal Court’s requests to extradite Saif al-Islam for trial in The Hague.
He is wanted by the ICC on war crimes charges, but Tripoli insists he will be prosecuted at home, where he could face the death penalty.
Among those who are expected to go on trial in August are Col Gaddafi’s intelligence chief Abdullah al-Senussi and ex-Prime Minister al-Baghdadi al-Mahmoudi.
Saif al-Islam is currently being held in the western Libyan town of Zintan, following his capture by militiamen at the end of 2011.
He was considered the most likely successor to Col Gaddafi before the uprising that led to his father’s downfall two years ago.
In January, Saif al-Islam Gaddafi appeared in Zintan’s court in a separate case on the accusations of trading information threatening Libya’s national security.
That trial was later postponed.