Three Americans "tourists" are on their way home from Cambodia Monday after being arrested in an ongoing federal sex tourism investigation.

The arrests are part of “Operation Twisted Traveler,” an effort by the U.S. Immigration and Customs Enforcement to identify and prosecute American sex tourists in Cambodia.

The suspects — Jack Sporich, 74, Erik Peeters, 41, and Ronald "John" Boyajian, 59 — are all convicted child sex offenders who have served time in U.S. prisons.

After their release, investigators say, the three headed to the most destitute neighborhoods in Cambodia, itself one of the poorest nations in Southeast Asia, where it is believed they once again sexually assaulted young boys and girls.

FOX News was given exclusive access to the suspects and video of their arrest.

Click here to see video.

Homeland Security Assistant Secretary for ICE John Morton stressed that Operation Twisted Traveler is still very much ongoing.

"Boarding a plane to a foreign land is no protection," Morton said. "If you molest children overseas and we find out, we will investigate you and we will seek to bring you back here to face justice. The arm of the law is long, it’s determined, and it’s looking for you."

Peeters bought a 13-year-old Cambodian boy from his parents for $2 and a bag of rice, and raped him five times, a federal affidavit alleges.

Investigators say the 41-year-old from Norwalk, Calif., thought he could get away with his crime by escaping to Cambodia, the capital of the billion-dollar sex tourism trade in Southeast Asia, where he is one of thousands of Western pedophiles who travel there to prey on children.

But local police and U.S. investigators had him under surveillance.

Now, he and two other California pedophiles are returning to Los Angeles on a jet departing from Tokyo.

Another of the men onboard was Jack Sporich, a 74-year-old that police call the ‘Pied Piper of Pedophiles.” He spent nine years in a California prison for molesting as many as 500 boys during camping trips.

After his release from Atascadero State Hospital, where he refused treatment, records show he traveled to Southeast Asia at least eight times, where sources say he rode his motor scooter through the poorest neighborhoods of Cambodia's capital Phnom Penh, dropping a trail of American dollar bills to lure young boys back to his home where they were allegedly sexually assaulted.

The final passenger, 59 year-old Ronald Boyajian, was convicted of 18 counts of sexual intercourse with minors in 1995 in Menlo Park, Calif. He was caught molesting a 10 year-old Vietnamese girl in an area called Kilo 11, a haven of child brothels 11 kilometers outside Phnom Penh.

“Cambodia in particular has been known for some time as a pedophile haven because there’s been a broken justice, no rule of law, and actually no laws on the books that would have been enforceable against these types of activities until recently,” said Jeff Blom, an investigator with International Justice Mission.

“We need to change the fear equation, make pedophiles fear going to jail.”

Cambodian police say other victims were believed to be given $5 or $10 after each sexual act and the children were photographed naked. Mothers of two of the abused boys lived on the street and sold their boys for up to $100 because, they said, “they needed the money.”

Investigators say all three sex offenders lived in or just outside the capital city of Phnom Penh while on their multiple trips to the Asian region in the last few years.

In the U.S. the men face charges under the Protect Act — a 2003 law that provides life terms for child sex offenders with prior convictions, a much longer sentence than offenders would get abroad.

Investigators say the men are part of a thriving billion-dollar sex tourism business. After a crackdown in Thailand on child sex, the industry has moved primarily to Cambodia where pedophiles molest Vietnamese girls and Cambodian boys with little risk of being caught.

ICE hopes the arrests, done in conjunction with federal prosecutors in Los Angeles, Cambodian police and two anti-child trafficking organizations, International Justice Mission and the human rights organization Action Pour Les Enfants, will send a message that police are watching. Since 2003, ICE has arrested 70 international sex offenders under the Child Protect Act.