Standing before an American court convicted of the most heinous of child sex crimes, the double lives of Australian citizen Mark J. Newton and his long-term boyfriend Peter Truong were laid bare.

‘‘Being a father was an honour and a privilege that amounted to the best six years of my life,’’ the American-born Newton, 42, told the court.

Double lives: Newton, right, with Truong and their son outside their Cairns home. Photo: ABC

Moments later Newton was sentenced to 40 years in prison for sexually abusing the boy he and Truong, 36 from Queensland, had ‘‘adopted’’ after paying a Russian woman $8000 to be their surrogate in 2005.

Police believe the pair had adopted the boy ‘‘for the sole purpose of exploitation’’. The abuse began just days after his birth and over six years the couple travelled the world, offering him up for sex with at least eight men, recording the abuse and uploading the footage to an international syndicate known as the Boy Lovers Network.