Airport police in Paris detained a six-year-old French girl for three days on suspicion that she had a fake passport.
The child was released after a judge ordered that she be placed in her mother's custody.
According to the New York Times, the case has caused indignation in France amid a sensitive debate over police treatment of waves of undocumented migrants coming to Europe in recent months.
The girl was detained at the Charles de Gaulle Airport near Paris after arriving from Cameroon, said a lawyer representing them.
She was traveling as an unaccompanied minor carrying all necessary documents, and her mother was waiting at the airport to greet her.
The police thought the girl's passport photo did not resemble her and suspected it to be a fake, according to the lawyer and the French Interior Ministry.
The girl, born in Paris, was held in a special police center for children for three days before she appeared before a judge, who asked the girl to identify her mother, seated across the courtroom, the lawyer said.