Beijing police are investigating the roles of around 100 suspects detained during operations against a large child pornography sharing network.

According to the police, the ring leader, a 19-year-old college student surnamed Sun, was arrested in Beijing earlier this year with 400 gigabytes of child porn on his computer. He was found to have posted 100 such videos online, attracting 20,000 hits and 7,000 replies.

Fluent in English, Sun stored the videos on an overseas server and posted them on foreign websites. He exchanged them for foreign pornography to share with domestic pedophiles, connected through QQ messenger, the police said.

Members of his QQ chat groups numbered in the thousands, but each group usually existed for less than ten days before re-grouping to avoid detection by police, said Zhang Min, in charge of the case.

Sun's network involved suspects in more than 25 provinces who regularly preyed on lone minors in remote villages or migrant workers' camps, he added.

"Few reported the abuse to police," said Zhang. "We are furious to find that so many children fell victim."

It was not until this March when his office was tipped off by American counterparts under the Department of Homeland Security that they knew the network existed.

"The ring used advanced technology to dodge China's cyberpolice. It is a signal that me must upgrade our skills and technology to meet the challenge," Zhang said.

Sun has been convicted of spreading pornography and sentenced to 18 months in prison while the investigation of the other suspects continues.

(Xinhua News Agency November 10, 2016)