A New Zealand man pretended to be a child to befriend other children playing online games before he exploited them sexually.
Jamie Edward Ireland faced the Victorian County Court today after pleading guilty to seven child sex offences, including two charges of using a carriage service for sexual activity with a person under 16.
Prosecutor Joshua Robins said the offending was sustained and had several aggravating features.
"It was covert," he told the court. "He adopted a child persona."
The charges also included one count of possessing child pornography.
Mr Robins said an aggravating factor of this charge was the fact the material depicted Ireland's victims.
Two thirds of the child pornography found in Ireland's possession was category two, out of a five category scale that classifies the severity of exploitation material, and one fifth was category five, Mr Robins said.
Ireland encouraged his victims to go to greater lengths of depravity, he said.
Judge James Montgomery, who will sentence Ireland on Thursday afternoon, said he didn't need convincing the offending was very serious.
"It's every parent's worst nightmare," he said.
Ireland started with gaming and gradually moved into sexual activity, Judge Montgomery said.
Defence barrister Rob Thyssen told the court Ireland had expressed regret and remorse after hearing the victim's statements.
"At the time he was on the road to self destruction," Mr Thyssen told the court.
Ireland will return to court on Thursday afternoon to be sentenced.