Activists Khaled al-Sayed, Mohamed al-Sayes, Nagy Kamal and Abdallah Mohamed were released Tuesday night, their families reported.
The four activists were arrested on the third anniversary of the 25 January uprising revolution while taking part in demonstrations in downtown Cairo.
Sayed was a member of the Youth of the Revolution Coalition which was a main organizing front for the revolution during its first 18 days.
The prosecution also issued release orders on Tuesday for 19 other detainees who were arrested in Cairo’s Abdeen neighborhood on January 25.
The Ministry of Interior started a crackdown on protests after the removal of former President Mohamed Morsi in July. According to the ministry, over 1000 were arrested on the anniversary of the revolution alone.
Many remain in prolonged detention under investigation without trial. Prominent activist Alaa Abd El Fattah is approaching 100 days in prison without trial with charges of calling for an unauthorized protest.
During his incarceration, Sayed released a letter detailing the torture that detainees are being subjected to, including electrocution and sexual abuse.
Activists and lawyers are also reporting stalling and delays in the release of detainees after they receive acquittals or release orders.
A group of minors arrested in Maadi on January 25 were acquitted on Sunday. Their lawyers however report that the police refused to release them and referred them back to National Security for interrogation. They were finally released on Tuesday.
Freedom for the Brave, a campaign working on the release of detainees, posted on its Facebook page on Tuesday that the release of the prominent figures is not sufficient and that it would continue to work for the release of all detainees, known and unknown.