A Canberra man who groomed a 12-year-old American girl for sex, after her mother pimped her out to him, will spend only 28 days in jail.

Thomas Keski Nummi Wilson was 22 years old when he groomed a girl in Colorado, United States over the internet.

His lawyers argued Keski Nummi Wilson established a genuine friendship with the girl, but then had inappropriate and explicit sexual conversations with her.

The ACT Supreme Court heard these conversations educated the young child in sexual matters she should not be exposed to and would have been extremely damaging to the child.

The court heard as part of their communication, Keski Nummi Wilson got the girl to send him pornographic images of herself.

He also sent the 12-year-old sex toys and sex aids and thousands of dollars in gifts.

To show he was genuine, Keski Nummi Wilson also sent a photograph of his photo ID from the University of Canberra and a copy of his driver's licence.

Both photographs clearly showed that Keski Nummi Wilson was 22 at the time.

The court heard Australian police were alerted to Keski Nummi Wilson when the FBI contacted them.

The young girl's mother, Julie Greiner, 43, was arrested after the girl's brother, Alex, alerted police.

Greiner was charged in the US with human trafficking of a minor for sexual servitude, pimping of a child and pattern sexual assault of a child.

She has since been jailed for these offences.

According to a warrant sworn in the Jefferson County Court in Colorado, Greiner received more than $10,000 from Keski Nummi Wilson.

Man holidayed in Hawaii with the girl, mother

The court was told Keski Nummi Wilson and his mother, Merja, travelled from Canberra to Colorado to meet the young girl and her mother.

They then all went together on a holiday to Hawaii, although it was stated in court that there was no evidence of any sexual encounter between Keski Nummi Wilson and the young girl.

During the sentencing hearing it was revealed Keski Nummi Wilson suffered depression and that this was brought on when he was abused sexually by a member of his family.

The court heard the alleged assault had occurred between the ages of 12 and 15 but that no charges had been laid against the perpetrator in his family.

On Thursday Justice Michael Elkiam sentenced Keski Nummi Wilson to two years in jail, with his sentence suspended after 28 days.