A man from Montgomery, Alabama, has been charged with child pornography and sexual exploitation after he faked his identity as pop sensation Justin Bieber and got young girls to perform sexual acts on the internet.

Christopher Patrick Gunn, 31, lured girls to go topless and perform sexual acts online, promising them free tickets to Justin Bieber's concert and backstage passes. When the girls realized that they were not talking to the real pop star, he threatened to post their images and videos on pornography sites.

The accused used Facebook to fake his identity. He apparently started the filthy act in 2009 and continued until recently till he was arrested March 20 when FBI agents executed a federal search warrant on Gunn's house. They seized a laptop and a cell phone containing images and videos of child pornography, reported blog.chron.com

From 2009 to summer 2011, he pretended to be a new kid on the block who needed to make friends. From November 2011, he started pretending to be the singer to lure young girls.

The girls, who have fallen in his trap, are aged between 9 and 16 and belong to different states such as Florida, Virginia, and California, according to federal authorities.

Gunn's first arrest was in March this year when he was charged with two counts of child pornography. But last week, he was again charged with 10 counts of sexual exploitation, three counts of interstate extortion and three counts of using an interstate commerce in furtherance of unlawful activity, Mail Online reported.

 The incidence came to light when three girls in their early teenage from Biloxi, Mississippi, informed the police about Gunn and his activities online.

They didn't want to play his game anymore, Donnie Dobbs, a Biloxi police detective, told the Sun Herald.

Gunn has been on a probation sentence in a Florida case, convicted of theft, burglary and other crimes.

This is not the first time a case of faking the singer's identity has taken place.

Earlier, New Jersey authorities arrested a Canadian man, Lee Moir, 34, of Toronto, Ontario, who pretended to be Justin Bieber to get young girls perform sexual acts on the internet. Moir also used Facebook as a medium to communicate to the girls.