Tara Barra, spokesperson for Libya's attorney general, said Saif and Senoussi will be put on trial after the completion of questioning of Senoussi.
Last week, the justice ministry announced that former prime minister al-Baghdadi Ali al-Mahmoudi will also be tried along with the other two.
Barra's announcement came amid an ongoing battle between Libya and the International Criminal Court (ICC) over where Saif should face justice.
In 2011, the ICC issued warrants against Senoussi, Muammar Gaddafi and Saif on charges of crimes against humanity stemming from the crackdown on protesters.
Muammar Gaddafi was killed by rebels near his hometown of Sirte in October 2011.
Saif's lawyers say their client would not receive a fair trial in Libya, because he could face the death penalty.
The Libyan authorities have repeatedly rejected requests to hand him over for trial in The Hague.
Tripoli: Slain Libyan leader Muammar Gaddafi's eldest son Saif al-Islam Gaddafi and intelligence chief Abdullah al-Senoussi will stand trial in Libya as early as next month, Xinhua reported Monday.
First Published: Monday, January 14, 2013, 23:23