The CNLD prisoners' rights group said Monday the 71-year-old Khadidja Bouraoui had been released under judicial supervision.
Her daughter, Amira Bouraoui, had been a prominent figure in the 2014 "Barakat" movement against then-president Abdelaziz Bouteflika's bid for a fourth term in office.
Earlier this month she had been arrested in Tunisia and faced deportation to Algeria, but was able to leave for France, sparking a diplomatic incident between Algiers and its former colonial ruler.
Algeria has accused France of assisting her "clandestine and illegal exfiltration" via Tunisia, and recalled its ambassador in Paris for consultations.
Bouraoui had been banned from leaving Algeria after being sentenced to two years in jail for "offending Islam" and for insulting the president.
The CNLD said a court had ordered arrested journalist Mustapha Bendjama and Bouraoui's cousin Yacine Bentayeb remanded in custody.
Algeria has also arrested Raouf Farrah, an analyst from the Global Initiative Against Transnational Organized Crime (GI-TOC).
The Geneva-based organization said he had been "visiting his parents with his wife and child when detained", and remained under arrest.
GI-TOC said it was "deeply troubled and concerned by Raouf's arrest and is following closely and working to understand the legal context and what he is being accused of".
Algerian authorities have not officially commented on the investigation into Bouraoui's departure from Algerian territory.
Algeria and France had gone through a diplomatic crisis in late 2021 but had started to mend fences with a high-profile visit by Emmanuel Macron last August.
