Casablanca prosecutors ordered El Mahdi Lyoubi into pre-trial detention on Wednesday after police held the rapper and filmmaker since Monday.
Lyoubi — known as Mehdi Black Wind — was stopped from boarding a flight to Marseille, where he lives, before being taken into custody.
The prosecutor’s office has not disclosed any charges, leaving the basis for the detention unclear.
The Moroccan Association for Human Rights called for his immediate release, saying the case raises freedom-of-expression concerns.
More than 500 artists, musicians and film professionals signed a Mediapart petition demanding the release of the outspoken critic of Morocco’s political system.