A 20-year-old man has been arrested in Germany on suspicion of engaging in an online campaign of cybergrooming and virtual sexual abuse of children, including pressuring a 13-year-old American boy to kill himself and livestream the act, authorities said Wednesday.

The German-Iranian man was arrested Tuesday. The man, whose name was not made public in line with German privacy rules, was taken into custody at his parents’ apartment in the northern city of Hamburg. Prosecutors have yet to decide whether to bring formal charges. He denied wrongdoing in a closed-doors appearance before a judge, authorities said.

“The acts exceed human imagination,” Hamburg Attorney General Jörg Fröhlich said at a news conference Wednesday, German news agency dpa reported.