Detectives have charged a 26-year-old man with more than 100 child sex offences against 33 children in Cairns.
The man groomed children online and bribed some victims to keep meeting with money and gifts.
The charges close a major investigation conducted by the Cairns Child Protection and Investigation Unit in what was called "Operation North Lithograph".
Authorities became aware of the 26-year-old Brinsmead man in December when he was arrested and charged with five child sex offences against five children.
The investigation led to identifying another 28 victims, including young boys and girls ranging from 11 to 16-years-old.
Police allege the man made contact with victims online, posing as a teenager on social media to lure them into meeting in person.
“We’re not just talking Facebook, we’re talking What’sApp, KickApp, Facebook Messenger and Snapchat,” Detective Inspector Geoff Marsh told reporters at a press conference on Tuesday.
The man remains in prison and will appear in Cairns Magistrates Court on March 9.