ElBaradei took his oath of office on Sunday before Egyptian interim President Adly Mansour.

ElBaradei was appointed as Egypt’s vice president for foreign relations almost a week after the military deposed president Mohamed Morsi on July 3 and declared the chief justice of Egypt’s Supreme Constitutional Court, Adly Mansour, as caretaker president.

He was initially tipped to lead the cabinet but his nomination was rejected by the Salafist Nour party.

ElBaradei’s swearing-in came on the same day as the Egypt prosecutors began questioning Morsi and the members of Muslim Brotherhood party over their escape from prison during 2011 uprising.

The probe follows allegations that Morsi along with about 30 senior Muslim Brotherhood members escaped from Wadi Natrun Prison during the uprising that toppled former dictator Hosni Mubarak two years ago.

Morsi and his colleagues are also accused of spying, inciting violence and damaging the economy.

The deposed president could face a long-term prison sentence if found guilty of colluding with foreign groups against the Egyptian state.

Meanwhile, the ousted president's supporters held fresh rallies in Cairo to demand his return to power.

MRKD/SHI