Egyptian authorities on Friday arrested the leader of the opposition April 6 Youth Movement at Cairo airport and transferred him to a police station for interrogation, airport officials said, dpa reported.
Ahmed Maher, who was listed on the arrival anticipation and travel ban registers, was detained for three hours upon arrival from the United States, before the Interior Ministry demanded his transfer.
Airport sources said he was detained over his movement's call a few weeks ago for people to protest in their underwear in front of the Interior Minister's house.
Maher had been in the US, where he attended a conference on Egypt's transition.
The April 6 Youth Movement was launched in 2008, when they promoted the call for a nationwide strike to be held on April 6 in solidarity with workers' strikes.
The movement was a key catalyst in the uprising to oust then president Hosny Mubarak in 2011.
The group supported Islamist President Mohammed Morsi against his rival, Ahmed Shafiq, Mubarak's last premier. However, the group started opposing Morsi's rule saying he had failed in achieving the revolution's demands.
In recent months, the number of complaints and charges from the public against activists and media professionals has been on the rise.