A man who posed as Justin Bieber online has been charged with more than 900 child sex-related crimes in Australia.The man, 42, masqueraded as the Canadian singer to gain explicit images from children, Queensland Police said.He was charged with 931 crimes, including three of rape, involving 157 alleged victims across the globe.Detective Inspector Jon Rouse called the allegations "frankly horrendous" and warned young fans of the singer and parents to be vigilant."The fact that so many children could believe that they were communicating with this particular celebrity highlights the need for a serious rethink about the way that we as a society educate our children about online safety," said Mr Rouse.Queensland Police confirmed the investigation also involved international authorities. According to local media they are German police and US Homeland Security.Fifty of the alleged victims were in the US, six were in Australia, while 101 were in nations police did not name.The man was already facing charges in Queensland of possessing exploitative material and grooming children, but the 931 charges were added this week after police searched his computer.He had been using "multiple online platforms" including Facebook and Skype to communicate with children, police said.The fresh claims, dating back to 2007, include three charges of rape and five of indecently treating a child under 12.Mr Rouse said the allegations showed "the global reach and skill that child sex offenders have to groom and seduce victims".He urged parents to help keep children safe online. The accused man will face a Brisbane court on 6 April.Source: BBC