Pavlensky has already admitted publishing a video showing a man masturbating, along with racy text messages sent to a woman.
The video prompted Benjamin Griveaux, a married father of three, to quit the race to be Paris mayor a month before the first round of voting.
Griveaux filed a complaint and politicians from across the spectrum have come to his defense, portraying the 42-year-old as a victim of a hatchet job.
Benjamin Griveaux stepped out of the race to become the next mayor of Paris last Friday. Photo: AFP
Pavlensky, 35, told AFP last Friday that he wanted to expose the “hypocrisy” of Griveaux and his campaign pledges to uphold family values.
Taddeo, a 29-year-old French law student, is believed to have been the recipient of the videos, which were sent in 2018 when she was having a relationship with Griveaux.
Griveaux's fall left Macron's La République en marche (LREM) party scrambling to find a replacement candidate for Paris mayor.
Health Minister Agnes Buzyn is set to take his place despite the daunting odds – Griveaux was already running in a distant third place before the scandal broke.
Pavlensky, who has a long record of provocative performances, received asylum in France in 2017 after several radical protests in Russia.
He was originally detained on Saturday on accusations he pulled a knife during a brawl at a New Year's Eve party in Paris, before investigators shifted their focus to the leaked sex video.
The pair have both been mise en examen (the French judicial system's equivalent of the charging process) over invasion or privacy and publishing sexual images without the consent of the person featured. Pavlensky has also been charged in relation to the brawl.
Publishing sexual images without the consent of the person featured in them carries a maximum term of two years in jail and a fine of between €45,000 and €60,000.