A US court has sentenced a 42-year-old Australian to 40 years prison for buying a boy for $8000, sexually abusing him with his partner over four years and handing him off to other paedophiles to molest.
US authorities had taken the child in October last year, after the couple's Queensland home was raided by a taskforce investigating child abuse cases.
The Australian pleaded guilty to conspiracy charges involving child exploitation.
Indiana attorney Joe Hogsett said the man had illegally adopted the child from an unidentified foreign country with the sole purpose to abuse him sexually.
''These men submitted this young child to some of the most heinous acts of exploitation that this office has ever seen,'' he said.
Investigators found pornographic recordings in several homes across the US after tracing the pornography to its source.
It is believed the men were identified last year as a Queensland couple. One of the men wrote to a gay community organisation in Queensland, complaining to be victimised by US authorities for being gay.
''Our son is our reason for living but we have no choice left but to give him up for adoption,'' he wrote.
District Judge Sarah Evans Barker believes the abuse also occurred during trips to Australia, the US, France and Germany, and said the man deserved a harsher punishment, but she did not want to subject jurors to such disturbing evidence.
A spokesperson from the Department of Foreign Affairs said: "We are providing consular assistance to two Australian men who were arrested by US authorities in February 2012 for alleged child sex offences."