Former France international Djibril Cisse was recently taken into custody and questioned by French police over the alleged blackmail plot.
Cisse was released by police on October 13 following a raid on his house at 6am in Paris.
Now French media agency AFP reports Benzema has also been taken into custody over the allegations.
AFP says Benzema visited the premises of judicial police shortly before 9am CET, before being placed in custody.
The matter relates to a judicial investigation opened in July over claims that Valbuena, who now plays for Lyon, was the subject of an extortion attempt.
In October a prosecutor said of Cisse’s arrest: “Djibril Cisse was taken into custody… in connection with a judicial investigation opened in the district court of Versailles on July 31 2015.”
The statement said it was “an offence punishable by at least five years in prison.”
Le Parisien had mentioned the Real Madrid star in connection with the investigation on October 15, saying his name appeared “peripherally” in wiretaps conducted as part of the probe.