A Cairo prosecution office has ordered the detention of Rifaa El-Tahtawi, ousted president Mohamed Morsi's chief-of-staff, for 15 days pending investigations into last December's clashes at Ittihadeya presidential palace.  

Asaad Sheikha, Morsi's deputy chief-of-staff, was also slammed with a 15-day detention order.

Both are being held at an unknown location with Morsi and a number of other aides since 3 July when the president was removed from office by the army amid mass nationwide protests against him and Muslim Brotherhood rule. 

El-Tahtawi, unlike Asaad Sheikha, is not a member of the Muslim Brotherhood or its political arm, the Freedom and Justice Party. He is a former diplomat who served previously as Egypt's ambassador to Iran and Libya. He was also the official spokesman of Al-Azhar, Egypt's highest Islamic institution.

At least five people were killed and over 600 injured when clashes broke out between supporters and opponents of Morsi outside Ittihadeya in Cairo's Heliopolis district last December. Morsi's opponents were protesting against a constitutional declaration he had issued 22 November 2012 extending his powers and shielding them from judicial review.

Morsi has been held incommunicado since his ouster 3 July. A week ago, a top Egyptian court ordered the detention of Morsi for 15 days pending investigations into his suspected collaboration with Palestinian Islamist group Hamas.