He is locked up in the Los Angeles Metropolitan Detention Centre, charged with attempted child sex trafficking, and faces the prospect of life in the US federal prison system without the prospect of parole. Michael Quinn is facing between 10 and 13 years behind bars. US authorities allege Mr Quinn, a Monash University-educated geneticist at a Melbourne IVF clinic, kept a dark secret from his travelling companions. On Saturday afternoon, two days after he landed in LA on Qantas flight 93, Mr Quinn caught an Uber to a hotel where he planned to meet with "like-minded men" and a six-year-old boy, according to the criminal complaint. In the hotel room, the Cartoon Network was playing on the TV and Toy Story-themed cupcakes were available to eat.

Mr Quinn, according to US authorities, also had $US260 ($A360) in his pocket. The money was to allegedly pay for the sex he planned to have with the six-year-old, who was yet to be presented by a pimp. Mr Quinn had also allegedly brought a camera, film and a monopod to support the camera. About 10 minutes after Mr Quinn arrived in the room, and after he had had a beer, chat and a Toy Story cupcake with the strangers, an undercover agent posing as a pimp came to the door and said "money time", according to the criminal complaint. "Quinn, clearly remembering the previous discussions where he had been told the price would be $US250 to sodomise the boy for approximately an hour, he pulled out his money and gave the pimp $US260," Aaron McClellan, a special agent for US Immigration and Customs Enforcement, wrote in the complaint.

"After Quinn paid the pimp, law enforcement came into the room and arrested everyone." Mr Quinn was the target of a meticulous operation by undercover agents from ICE's Homeland Security Investigations unit. It began in April when an agent accessed a social networking site with online groups who "expressed their sexual interest in children" and found a post from "Mick" who stated he was travelling from Australia to LA. Mick, who US authorities say has been identified as Mr Quinn, allegedly told the undercover agent he was "looking for sex with children" and while "he liked both boys and girls, his favourite were boys, aged 5-10". "Would love to share one with you mate," Mr Quinn allegedly wrote.

Mr Quinn also allegedly stated he was "a bit nervous" and suggested they "party" with drugs before. "The only reason why I'd want to party is to know you're not cops," he allegedly told the undercover agent. Special agent Kelly Kottas, group supervisor of the HSI-led task force, said Mr Quinn was stunned when authorities burst into the room and told him he was under arrest. "He was shocked and very nervous," Agent Kottas said. Mr Quinn was charged with attempted sex trafficking of a minor, which carries a minimum sentence of 15 years and a maximum of life without parole.

He was also charged with one count of travelling to the US for the purpose of engaging in illicit sexual conduct with a minor, which carries a maximum penalty of 30 years in prison. Agent Kottas said they believe Mr Quinn's friends on the US trip had no idea "where he was at or what activity he was engaged in" when he was arrested. Mr Quinn is expected to appear in the US District Court on Friday (LA time). AAP