Egyptian authorities on Wednesday detained senior Muslim Brotherhood figure Essam al-Erian, one of the last few leaders of the Islamist movement to have escaped a security crackdown, the interior ministry said.
Security forces arrested Erian, deputy leader of the Brotherhood's Freedom and Justice Party, at dawn in east Cairo where he had been in hiding.
Pictures of Erian circulating on social media, apparently taken during his arrest, showed him smiling and making a gesture symbolising the rejection of the military's ouster of Islamist president Mohamed Morsi in July.
Security forces launched a massive crackdown on Morsi's supporters in August, violently dispersing two protest camps in Cairo and making mass arrests.
More than 1,000 people have been killed since Morsi's ouster -- mainly his supporters -- and the authorities have detained some 2,000 Islamists, including most of the Muslim Brotherhood's leadership.
Morsi himself has been held incommunicado in military custody since his ouster and is due to go on trial on November 4.
The arrests have not deterred Morsi's supporters from organising demonstrations, which have deteriorated into deadly street fights pitting them against opponents and security forces.
Morsi's detractors accused him of poor governance and charged the Muslim Brotherhood with trying to monopolise power following the 2011 overthrow of longtime ruler Hosni Mubarak.
His supporters deny such allegations and point to the Muslim Brotherhood's victories in a series of polls held after Mubarak's overthrow.