Egyptian prosecutors slapped Saturday ousted president Mohamed Morsi with a fresh charge of "insulting the judicial authority."
Morsi's detention was extended by four more days pending investigations into the new charge.
Morsi is still held incommunicado since his ouster by the armed forces following protests 3 July.
Throughout his one-year rule, Morsi's administration was at odds with the judiciary. The peak of the confrontation came in November 2012, when Morsi released an abrupt decree sacking the prosecutor general and immunising the Islamist-led Shura Council and Constituent Assembly from judicial dissolution.
On 26 July, Morsi received his first 15-day detention order pending investigaions into espionage and jailbreak charges.
He is accused of collaborating with Hamas to orchestrate his escape from Wadi El-Natroun Prison in early 2011, as well as destroying police records during the 2011 uprising. In addition, he faces charges of espionage, and of attacking police stations with the intent to kill and abduct police officers and prisoners during the 2011 uprising.
Morsi, along with dozens of other members of the Muslim Brotherhood, escaped from prison during the 2011 revolution that toppled predecessor Hosni Mubarak. The Palestinian Hamas and Lebanese Hizbullah groups have been accused of aiding in the plot to attack prisons, resulting in the release of inmates.
Most of the Brotherhood's top leaders are currently detained on charges of inciting violence during recent or past clashes.