Robert Hunter, 35, of Middlesbrough, pleaded guilty to 15 charges of causing or inciting a child to engage in sexual activity and 14 of making indecent photos of children, The Mirror reported Monday.
Prosecutors said Hunter used social networking websites such as Facebook, Skype and MSN to abuse girls as young as 9 years old from Europe, Asia, Canada and the United States.
"Over the course of 2010, 2011 and 2012, Hunter, using a number of online aliases, had pretended to a number of very young girls that he was a teenager," prosecutor Richard Bennett said. "On each occasion he was able to disguise his true age and identity by the clever use of images of young boys or by pretending that his computer wasn't working properly. As a further demonstration of the naivete and innocence of his victims, he was also able to persuade some that he was the music artist Justin Bieber. He did this in order to dupe and encourage these young girls to strip on webcams and perform sex acts for him."
Investigators found more than 800 videos and images on Hunter's computer, all of which were allegedly made by the defendant.
Police began investigating Hunter when a girl from Tasmania that he contacted later told police about the online interaction.
"This is one of the most serious cases on Internet abuse that the courts have dealt with," Judge Peter Bowers said at Hunter's sentencing hearing. "It's a warning to all parents of teenage children of what can be done via the Internet."