British former undercover reporter Mazher Mahmood is being charged with conspiracy to pervert the course of justice. The specific issue is the drug case against singer and X Factor judge Tulisa Contostavlos, in which Mahmood is accused of having given false testimony.
Crown Prosecution Service says that it will have to review more than 30 court cases in which he testified.
Mazher Mahmood, popularly known as the "fake Sheikh" for the costume he frequently wore while undercover, worked for New of the World. He denies any wrongdoing and says that he will "vigorously contest it at court."