Security forces arrested in the early hours of Monday the director of the Egyptian Commission for Rights and Freedoms Ahmed Abdallah from his home in New Cairo, the commission said in a statement.
The reasons behind Abdallah’s reported arrest are unclear.
The interior ministry has not yet commented on the commision's statement.
Abdallah’s arrest comes during a wave of arrests of activists ahead of protests planned on 25 April against Egypt’s acknowledgment that the two Red Sea islands of Tiran and Sanafir belong to Saudi Arabia.
The commission’s brief statement called for Abdallah’s immediate release.
The commission focuses on lifting injustices, whether political, economic, cultural or other, and stresses the need for a “state of law” that would maintain citizens’ rights and freedoms.