Muslim Brotherhood firebrand Mohamed El-Beltagy will be detained for 30 days, judicial sources have said, as a crackdown on Islamists continues.
El-Beltagy, who was arrested on Thursday in a village outside Cairo, released a video message recorded in hiding hours before his detention urging mass rallies against the "military coup" that deposed former president Mohamed Morsi.
An ex-member of parliament, El-Beltagy stands accused of a myriad of charges including attempted murder, inciting violence and chaos, and damaging public property.
Following hours-long questioning in the presence of his lawyer, he denied the allegations and claimed video and audio evidence against him was trumped up, Al-Ahram Arabic news website reported.
His 17-year-old daughter Asmaa was killed during a bloody police raid on a pro-Morsi protest camp in north-eastern Cairo on 14 August, which left hundreds dead and sparked days of deadly clashes between Islamists and security forces.
The 85-year-old Muslim Brotherhood – which operated underground for decades until the fall of autocrat Hosni Mubarak in 2011 – has been hit hard by a broad clampdown on its leaders and members following the ouster of Islamist president Mohamed Morsi, a senior member of the group.