The head of the Prisons Department transferred General Hassan Abdel Rahman, head of now-disbanded State Security to the Police Hospital in Agouza on Thursday for bladder surgery.
The state-owned MENA news agency said that he may have prostate cancer.
Abdel Rahman along with ousted president Mubarak, ex-Interior Minister Habib al-Adly and five of his aides were remanded pending a verdict on 2 June in the case of killing demonstrators during January 2011 revolution.
Two stories of the police hospital were evacuated and two officers from the National Security Agency were deployed to secure the floor where he is being hospitalized, sources told Al-Masry Al-Youm.
Abdel Rahman was transferred amid tight security procedures that began Wednesday until he reached the hospital and was received by the hospital chief for medical tests before the operation.
Several former regime figures have undergone medical treatment while in custody, including Adly, former Speaker of the People’s Assembly Fathi Sorour, former presidential chief of staff Zakariya Azmy, and former Housing Minister Ibrahim Suleiman.
Edited translation from Al-Masry Al-Youm