Four people, including former France international Djibril Cisse, have been taken into custody in France as part of an investigation into an alleged blackmail attempt.
AFP news agency, citing an unnamed police source, said the case concerns a suspected attempt to blackmail France international Mathieu Valbuena over an alleged sex tape.
According to a police statement quoted in Le Parisien, Cisse, 34, was detained by judiciary police in Versailles outside Paris. He was later released without appearing before a judge.
The statement read: "Djibril Cisse was taken into custody by members of the regional directorate of the judiciary police of Versailles as part of a criminal investigation opened at Versailles regional court on July 31, 2015."
The statement also said the investigation targeted blackmailers suspected of being involved in a criminal conspiracy "with a view to preparing a crime punishable by at least five years' imprisonment."
Versailles prosecutor's office also confirmed that three other people were put in custody on Tuesday morning, but a prosecutor's spokeswoman said the identity of the victim would not be revealed officially "out of respect for his/her private life."
Sources close to the case told AFP that the four were taken into custody on Tuesday morning following "an attempt to extort money" from Valbuena, 31, allegedly by claiming to have a "sex tape" he featured in.