South Giza prosecution has appealed against a decision to release detained Islamist leader Abul-Ela Madi, Al-Ahram Arabic news website reported.
Hours earlier, a court in Giza had ordered the release of the Wasat Party leader on LE10,000 bail.
"If the prosecution does not appeal the verdict today, we will pay the bail and my father should be released as he is not detained over other cases," Ahmed Abul-Ela Madi, Madi`s son and lawyer, told Ahram Online before prosecutors submitted their appeal.
Madi is being held in Tora prison and faces accusations of inciting violence during clashes at Giza's Nahda Square and in Bein El-Sarayat between opponents and supporters of ousted president Mohamed Morsi.
Madi is accused of making inflammatory speeches to Morsi supporters.
The Wasat Party founding member is known to be a staunch supporter of Morsi.
The party was founded in the late 1990s by defectors from the Muslim Brotherhood, the Islamist group to which Morsi belongs.