A British child sex offender who paid an undercover US agent for sex with a nine-year-old boy ran an online group looking for children to abuse, prosecutors say.
Paul Charles Wilkins, of Littleport, Cambridgeshire, went to California in January to meet boys to have sex with.
He also planned to meet a group men to have sex with boys in the UK at Easter, US legal papers show.
Wilkins, who could face life in jail, will be tried in the US in July.
The 70-year-old, who holds dual UK and US citizenship, was jailed in the UK in 2011 after pleading guilty to offences relating to indecent images of children.
He was on probation when he left the UK on 31 January this year.
He had told his probation officer he was going house-hunting in the US, according to an affidavit written by a Homeland Security Department special agent working on Wilkins’ apprehension.
The document, which tells how Wilkins was caught in an undercover sting, was sent to the BBC by the US Attorney’s Office in Los Angeles.
Wilkins was searched by customs officers when he arrived at San Francisco Airport because of his previous conviction in the UK, but nothing illegal was found.
However, another court document shows Wilkins managed to “transport and ship” a laptop containing pornographic images from the UK to the US.
An undercover agent made contact with him via an online group administered by Wilkins, and used by people with a “sexual interest in children”.
The group described itself as “a safe place for dads and sons who enjoy relations”.
Using a pseudonym, Wilkins told the officer he had come to California after the father of two boys, aged 10 and 12, had promised him he could have sex with his children. However, once he arrived, the father stopped communicating.
The affidavit further states Wilkins confided he was hoping to meet up with a group of men “to have sex with a minor child” in Palm Springs and had plans to meet with a similar group of men in the UK at Easter.
A second undercover agent was brought in as a “pimp”, offering Wilkins a nine-year-old Mexican boy whose family needed money to pay off debts incurred coming to the US.
Wilkins was arrested on 11 February at a rented Palm Springs apartment after handing over $250 (183) to the agent for his “share” in the child.
After claiming he thought he was meeting a 16-year-old, Wilkins later admitted he knew the boy was only nine, according to the papers.
Wilkins, described by US Attorney Eileen M Decker as a predator, was charged with travelling with the intent to engage in illicit sexual conduct with children and attempted sex trafficking of children.
Earlier this month additional pornography and transportation charges were added.
He will face trial in the US in July.