Police say Italian authorities helped them catch a man involved in distributing pornography depicting children as young as two.
In the Hamilton High Court on Friday, Bradford Pascoe was sentenced to preventive detention on 70 charges including sexual violation, indecent assault and distributing objectionable material.
The 38-year-old Te Awamutu man knew all three of his victims, who were aged between two and six.
He must serve at least eight years before he is eligible for parole.
Detective Inspector Chris Page says Pascoe was arrested in Christchurch last July during an investigation involving Italian authorities into an international porn ring circulating and obtaining child pornography through the internet.
Mr Page says the Italian police were key to uncovering Pascoe's offending.
"He was coming to notice to police for some other matters and it was just a matter of good timing and things sort of all lining up together.
"But in essence, unless the Italian authorities had come to us, we may never have uncovered the depth of this man's offending."
Mr Page says Pascoe tried to flee from authorities and for a few months was able to evade them, during which time he continued to offend.
Pascoe's lawyer, Bruce Hesketh, says his client was expecting a long jail sentence, but not preventive detention.
He says Pascoe wanted to take part in restorative justice with his victims, but their parents declined.