A Norwegian man has been charged with forcing more than 300 teenage boys to perform sexual acts, state prosecutors in Oslo said late Tuesday.

The 26-year-old, identified in the media as a football referee, is alleged to have targeted boys using internet forums and the Snapchat messaging app. Passing himself off as a girl, he reportedly promised to supply erotic photos if his victims agreed to send him videos of themselves masturbating.

Read more: Suicide over sex video highlights widespread internet problem

He then threatened to publish the videos online if the boys refused to keep sending him new recordings. Police reportedly found more than 16,000 films on his computer.

Suspect to face court in 2019

The prosecutor's office said the suspect had preyed on more than 300 boys between the ages of 13 and 16 since 2011. Some of the boys had allegedly been raped. The victims were from Norway, Denmark and Sweden.

"The case is a serious one, and it is the biggest case of sexual abuse in Norway to date," state prosecutor Guro Hansson Bull said in a statement.

Read more: Over 1,000 youths charged for sharing underage sex video

The suspect's lawyer Gunhild Laerum told broadcaster NRK that her client "admits the facts," but is yet to respond to each individual charge. He has been in custody since 2016 and is expected to face court early in 2019.

nm/rt (AFP, dpa)

Each evening at 1830 UTC, DW's editors send out a selection of the day's hard news and quality feature journalism. You can sign up to receive it directly here.