French footballer Karim Benzema could face preliminary charges as part of a blackmail investigation over a sex tape involving another player.

A judicial source said Benzema will be taken before a judge later on Thursday after being held overnight by police for questioning.

The judge will decide whether the Real Madrid striker should be charged.

Investigators are trying to find out if he played a role in the extortion attempt targeting fellow French international Mathieu Valbuena, and if he tried to blackmail the Lyon player.

Three people have been handed preliminary charges over the case since October.