Alaa Abdel-Fattah and 23 other activists have been detained on the first day of their retrial for breaking the protest law.
Judges also ordered the arrest of another defendant who did not attend the court session.
The retrial will resume on 11 November.
Abdel-Fattah and 24 other activists are appealing their 15-years prison sentences for violating the protest law.
On 11 June, they were found guilty of organising an illegal protest, rioting, destruction of public property and using violence against the security forces.
They were also fined them LE100,000 (about $14,200) each.
The protest law, passed last November, stipulates that its violators face long prison sentences and hefty fines. The law has been criticised by many pro-democracy groups and political parties who, along with Egypt's National Council for Human Rights (NCHR), have called for its amendment.
Abdel-Fattah, Mohamed Abdel-Rahman (Noubi) and Wael Metwally were the only defendants imprisoned upon the original verdict. They were released on 15 September pending their retrial.
On Monday, Abdel-Fattah posted a selfie on Twitter with a caption saying: "Selfie at [the courthouse]. At 8:45 AM. And the geotag is a witness. So no one say [this time] that we are sentenced to prison in absentia."
The sarcastic tweet stems from Abdel-Fattah's claim that the first verdict was legally questionable because security forces had prevented him from entering the courthouse to attend the trial.
Relatives and supporters of activists detained for breaking the protest law have started a hunger strike in solidarity with the detainees. Inside prisons and detention cells, tens of detainees have also participated in the strike.
Sanaa, Abdel-Fatah's sister, also on hunger strike, was sentenced yesterday to three years in jail also for breaking the protest law, along with 23 other defendants.
The hunger strike campaign is calling for the repeal of the protest law and the release of all detainees who were imprisoned under its provisions.
NCHR previously stated that they had been asked to participate in discussions on amendments to the law. However, shortly afterwards a cabinet spokesman said there were no plans to amend the law.
Hundreds of Islamists, as well as liberals, have been sentenced to prison for violating the law.