Judge Mostafa Hassan Abdallah on Saturday recused himself from presiding over the new trial of former president Hosni Mubarak in a chaotic hearing that lasted just seconds.
Abdallah sent the case to the Court of Appeal, which will then refer the trial to a new circuit, as civil society lawyers attending the trial shouted: "The people want the execution of the president."
In October, the same judge had acquitted the defendants in the infamous "Battle of the Camels" trial, who were accused of sending men on camels and horses to break up a protest during the 2011 uprising that toppled Mubarak.
Moments before the trial began, the 84-year-old Mubarak, dressed in white and wearing sunglasses, appeared combative and proud as he waved to supporters from the defendants' cage.
His sons Alaa and Gamal, who are also facing a new trial for corruption, appeared to be in good spirits as they smiled and chatted to their father, who was sitting up in the dock.