John Wrenshall could face up to 50 years in prison when he is sentenced Monday in a Newark, New Jersey, federal court.
Wrenshall pleaded guilty to three counts including conspiring to engage in sex tourism and to producing and distributing child pornography.
The 63-year-old detailed graphic abuse of boys as young as four.
Assistant U.S. Attorney Lee Vartan says authorities discovered Wrenshall was running a brothel for pedophiles in Thailand after confiscating computers from Union City, New Jersey, resident Wayne Corliss.
Corliss is serving a 20-year sentence after admitting he traveled to Thailand to have sex with at least two boys.