Christina Aguilera is ready to call the cops. On Wednesday, reports Reuters, the "What a Girl Wants" singer, 21, threatened to initiate legal action against the distributors of an online porn video that claims to include sexually explicit images of her. "It has recently come to our attention that certain pornographic Web sites are posting sexually explicit photographs and video footage on the Internet fraudulently representing that it is Christina," Aguilera's Web site stated under a heading labeled the "official statement on Adult Tape Rumor." "Christina's legal representatives have contacted the Web site hosts, and Christina plans to vigorously pursue all necessary action against the individuals responsible, including if necessary, initiating criminal proceedings," the message goes on to say. "The video clips advertised . . . are of a woman with blonde hair shown only from the back -- the person in the video is not Christina." Furthermore, says the statement, "the person who claims to have taken the video is not, and has never been, associated with Christina or her management." Several celebrities, including "Charmed" star Alyssa Milano, have taken legal steps to halt the appearance of what turned out to be doctored images and faked videos featuring celebrity lookalikes.