Egyptian security officials say a prominent activist and labour rights lawyer has been arrested on an array of charges including belonging to an outlawed group.
The officials said Haytham Mohamedeen, arrested on Friday, is a member of the Revolutionary Socialists movement.
Amnesty International criticised the arrest as "another attack on the right to freedom of expression and association" and called for his release.
In 2016, Mohamedeen was arrested and later released over calling for protests against Egypt's transfer of two strategic Red Sea islands to Saudi Arabia.
Egypt has waged a massive crackdown on dissent since the 2013 overthrow of an elected Islamist president after mass protests against his one year divisive rule.
The officials spoke on condition of anonymity because they were not authorised to speak to the media.