No date for the hearing has been set yet and investigators want to proceed as discreetly as possible, even considering travelling to Spain to hear the Real Madrid player, the source told Reuters.
Benzema's agent said the player had not been summoned.
"He has not received any notification," the agent, Karim Djaziri, told Reuters.
Ribery's lawyer, Sophie Bottai issued a statement to say he was only questioned because he knew somebody close to a person targeted in the inquiry.
Govou's lawyer, Thierry Braillard, told Reuters on Wednesday: "Sidney Govou has nothing to do with all this. Some are suggesting he could be close to a procuring network but it's absolutely not true."
French media suggested the players were clients of a night club in Paris's posh Champs-Elysees district that allegedly featured escort girls.
Govou's lawyer and Benzema's agent both told Reuters those two players had never been to that night club.
Ribery is France's most popular player since Zinedine Zidane, who retired after his infamous headbutt in the defeat by Italy on penalties in the 2006 World Cup final.
