An Egyptian court on Tuesday ordered that the trial session of ousted president Mohamed Morsi and ten others on charges of spying to Qatar be held as a closed session, citing national security concerns, state news agency MENA reported.
Morsi faces charges of using his post to leak classified documents to Qatar, with the help of his secretaries and other defendants.
Presiding judge Mohamed Fahmy of Cairo criminal court also issued a gag order on Tuesday's session as the court examines the evidence.
The classified documents allegedly include information on general and military intelligence, the armed forces, its armaments and the state's policy secrets.
Other charges include leading and joining an outlawed group -- the Muslim Brotherhood -- which aims at changing the political regime by force, and attacking army and police posts and public property.
Three of the defendants are being tried in absentia.
Morsi is facing three other trials, one on separate charges of espionage, one for escaping from prison during the country's 2011 revolution and inciting his supporters to kill protesters opposed to his rule during his time in office.
A security crackdown on Morsi, the Brotherhood, and their supporters has left thousands in jail, and hundreds facing trials on a variety of charges.
Hundreds of Morsi supporters have been given death sentences in court verdicts in the last year; they are currently being appealed.
Cairo and Doha have been witnessing on and off strains in relations since Morsi's ouster and the rich Gulf nation's hosting and support for fleeing Brotherhood members.
Relations slightly improved amid a Saudi-sponsored initiative under late King Abdullah, before diplomatic tensions soared again.