A Bulgarian court has ruled that a French citizen with family ties to the attack on the Charlie Hebdo satirical newspaper in Paris will be extradited to France to face terror charges.

The Sofia City Court announced on Tuesday that 20-year-old Mourad Hamyd didn't take advantage of a three-day deadline to withdraw the approval he had given to be sent back to France.

Hamyd was arrested on a French arrest warrant in Bulgaria on July 29. French authorities say they suspect he planned to join the Islamic State group in Syria or Iraq.

Hamyd, who has denied the allegations, is the brother-in-law of Cherif Kouachi, one of the men who attacked Charlie Hebdo in January 2015.

The extradition legally must be take place within the next seven days.