An investigation into a group's attempts to extort Mathieu Valbuena using a sex tape, has reportedly seen Karim Benzema arrested, according to French news agency AFP.

French police are investigating an alleged plot to blackmail Benzema's fellow France international Valbuena.

Retired striker Djibril Cisse has previously been questioned in relation to the matter before being released without charge. 

And AFP reported on Thursday (AEDT) of Benzema's apparent arrest, with the striker having reportedly visited premises of judicial police before being placed in custody.

The 27 year-old is injured and therefore missed Madrid's UEFA Champions League (UCL) win over Paris Saint-Germain on Wednesday.