"If a minister was under formal investigation, they would not be in the government. In a way, it's the same for the France team,", Valls told Europe 1 radio.
Real Madrid striker Benzema was put under formal judicial investigation last month in connection with an alleged attempt to blackmail Olympique Lyonnais forward Valbuena with the use of a sex video.
Both players were omitted by coach Didier Deschamps when he picked his squad for friendlies against Germany and England last month.
Benzema has been forbidden by a prosecutor to be in contact with the people linked to the investigation.
(Reporting by Julien Pretot. Editing by Patrick Johnston)
