Police say an international paedophile ring with victims as young as 18 months old is among the worst investigations they have conducted.
One of three New Zelanders arrested in the sting, Aaron John Ellmers, 41, pleaded guilty to more than 60 charges including sexual violation of children, stupefying, making an intimate visual recording and dealing in people for sexual exploitation when he appeared in the Hastings District Court on Tuesday.
Another man, whose name is suppressed, has admitted similar charges. A third is yet to appear in court. his name is also suppressed
Four New Zealand children ranging in age from 13 months to 13 years were involved and have been rescued.
A summary of facts outlining Ellmers offending shows he paid a 10-year-old for sex, and offered $500 to sexually assault a toddler.
Ellmers is a convicted paedophile who served time in an Australian jail before being deported to New Zealand in 2008.
Head of the Online Child Exploitation Team, detective senior sergeant John Michael says all the men involved knew the victims and their families.
He says the abuse is one of the worst cases New Zealand police have been involved in but say they are relieved they have been able to rescue the four boys.
Detective senior sergeant Dave Greig who heads the Eastern District Child Protection Team says investigators are grateful for the guilty pleas, which will spare a number of young victims and their families the ordeal of appearing at a trial.
The judge convicted Ellmers and remanded him in custody for sentencing in the Napier High Court on May 7.