Police have vowed to hunt down every member of an international paedophile network that sexually abused a boy who was trafficked by his adoptive parents.

Australian man Peter Truong and his partner Mark Newton bought the child, who the ABC will call Boy 1, from Russia in 2005.

His birth papers were falsified to list Newton as his biological father, paving the way for Boy 1 to be adopted and brought to Queensland.

Police say the men allowed at least eight men in several different countries, including Australia, the US, Germany and France, to molest the boy when he was between two and six years old.

US authorities have also found videos involving two more boys at Truong and Newton's Cairns home.

At the weekend, Newton was sentenced to 40 years in jail for his crimes. Truong is awaiting his sentence, while two other American men have also been charged.

Queensland police officer Jon Rouse, who investigates online child exploitation as part of Taskforce Argos, says authorities will not rest until all the men involved in the network are behind bars.

"With this network, rest assured that we will pursue them to the ends of the Earth to make sure each and every one of them faces justice for what their role has been in crimes against this child," he told 7.30.

"The purchase of the child for the explicit and sole purpose of exploiting him across a network of men is incredibly depraved and very sad tale for that little boy."

Truong and Newton evaded detection for six years, until a chance discovery exposed their depraved life and their paedophile network.

In 2011, New Zealand authorities discovered images revealing the boy had been used in child pornography.

They alerted Taskforce Argos and Queensland police raided the couple's house, just after the men and the boy had left for the US.

Police seized computers, electronic equipment and documents that uncovered high-definition video and images of child exploitation.

One video showed Boy 1 performing sex acts on Newton with a disturbing level of sophistication when he was not even two years old.

When he turned five, in one month alone Newton videoed himself engaging in sexual activity with Boy 1 on more than a dozen different occasions.

"One way they controlled and manipulated this child was to appear to the outside world as a good parent," said Steven Debrota, the deputy US attorney in Indianapolis.

"One of the things they did was they trained this child how to answer questions for particular investigators.

"So this was a psychological manipulation of the child."

ABC local radio presenter Ginger Gorman, who interviewed Truong and Newton before their crimes were exposed, agrees the pair put on a loving front.

"I felt no sense anything was wrong. For all intents and purposes this appeared to be a loving family and a loving household. I've gone over and over about it in my brain and I did not feel anything was wrong," she said.

Videos show other boys abused

US authorities also found videos involving two more boys at Truong and Newton's Cairns home.

"I can't say too much about the identity of that child," Mr Debrota said. "I can say that the victimisation of Boy 2 occurred in Australia.

"Under US law we can't say very much to identify Boy 1 or Boy 2, but it is the case and we can confirm that the conspiracy we allege involving Boy 1, Boy 2 and others was international in scope."

Police also found chat logs between Truong and Newton and a New Zealand man in which they bragged about how they had been having sex with Boy 1 since he was little.

They also bragged they had given him to several other men around the world for sex, including two American men who were being investigated by police.

Mr Debrota says the two US men allegedly became involved with Boy 1 when he was aged five.

The four men form part of a network known broadly as Boy Lovers - men who believe the sexual abuse and rape of boys aged between two and 10 is a form of consensual love between man and boy.

In 2009 the network's chatboard was smashed in a series of global raids, with several Australian men arrested.

Boy 1 remains in state care in the US.