Real Madrid striker Karim Benzema will appear in court on Thursday in connection with alleged blackmail over a sex tape involving fellow French international Mathieu Valbuena, after spending the night in custody.

Benzema, 27, was driven away from the police station in Versailles outside Paris in a police car with tinted windows, AFP journalists saw.

"Karim Benzema has been taken to the court to appear before an investigating magistrate who will decide what happens next in the procedure," the prosecutor's office said.

Investigators are trying to determine the extent of Benzema's involvement in an attempt to extort money from Valbuena after a sex tape found its way into the hands of suspected blackmailers.

According to an investigation source, Benzema mentioned the video to Valbuena when the French national team met for training last month, ahead of matches against Armenia and Denmark.

Benzema's lawyer said he had played "no part" in the plot and was keen to clear his name.

The centre-forward is a key part of the French national team with 27 goals in 81 appearances and is one of the biggest names in the star-studded Real Madrid squad.

Source: AFP