Ater 36 hours of detention and interrogation, the judge on Sunday ordered Benattia to be held in custody.
Another investigation was also opened over a separate alleged armed assault in August in which her boyfriend, Thomas Vergara, was wounded in the back.
Benattia may face charges of aggravated violence in that case.
A group of young people waited outside the court in the Paris suburb of Nanterre to get a glimpse of her.
Benattia, who denies any wrongdoing, rose to fame last year when she uttered "hello? I mean hello" in horror after learning that fellow female contestants had not brought shampoo with them on a reality TV show.
Firemen were called to a hotel in Boulogne-Billancourt near Paris in the early hours of Friday after the 22-year-old, who has now become a television commentator known by her first name Nabilla, apparently had a fight with Vergara, whom she met on reality TV.
Vergara had several knife wounds in the chest and his situation was considered serious though not life-threatening.
According to her initial statement, the couple was assaulted by three people and Vergara was injured when he tried to stop them, another police source said.
However, under subsequent questioning, Nabilla told investigators Vergara had taken cocaine and accidentally stabbed himself during a violent dispute with her.
Nabilla's famous expression spawned countless parodies, including one video where she calls a visibly irate Hitler, and inspired several ad campaigns, prompting the curvaceous brunette to have it registered as a trademark.
She had been taking part in the fifth instalment of "The Angels of Reality TV" — a show that groups together candidates and stars of other, previous reality TV shows — when she uttered the phrase.
"Hello? I mean hello? You're a girl and you don't have shampoo, hello? Hello! Do you receive me? You're a girl and you don't have shampoo. It's as if I tell you, you're a girl and you don't have hair," she said in shock in an episode broadcast in March 2013.
Originally from Geneva and carrying French and Swiss nationality, she started appearing in reality shows in 2011.
She went on to front her own reality show called "Hello Nabilla" about her life and family, much like her idol, US reality star Kim Kardashian.
She has also modelled for Jean-Paul Gaultier, published a book and appeared in the French edition of Vanity Fair.
NABILLA IN PICTURES