The three previously convicted sex offenders were the first to be charged under "Operation Twisted Traveler," an initiative targeting problems in Cambodia, which authorities described as ground zero for the crimes.
"Let their arrests serve as notice to any other person who might be tempted to evade justice by victimizing children outside of this country," said John Morton, head of Immigration and Customs Enforcement. "Boarding a plane to a foreign land is no protection."
Ronald Boyajian, Erik Peeters and Jack Sporich arrived in Los Angeles late Monday escorted by U.S. authorities after being arrested in February by Cambodian police, said Thom Mrozek, a spokesman for the U.S. attorney's office.
The three suspects were named in separate criminal complaints filed in April and May related to child sexual exploitation. They are expected to appear in court Tuesday. It was not immediately clear if the men have lawyers in the U.S.
ICE has stationed an agent in Cambodia full-time for at least a year to focus in large part on such cases.
Boyajian, 49, of Menlo Park, is accused of traveling to Cambodia in September 2008 and paying a 10-year-old Vietnamese girl to perform sex acts.
Peeters, 41, of Norwalk, engaged in sex acts with at least three Cambodian boys, authorities said. He gave their parents money and rice, and paid two of the boys between $5 and $10, the criminal complaint said.
Sporich, 75, of Sedona, Ariz., sexually abused at least one Cambodian boy, authorities said. Witnesses claim Sporich drove his motor bike through the streets of Siem Riep, dropping Cambodian currency to attract children.
Several boys stayed at his home in Cambodia, which had a swimming pool, water slide, video games, toys and clothing, authorities said.
All three men were charged under the Protect Act, which became law in 2003 and made it easier for U.S. authorities to prosecute people for overseas sex crimes. ICE has made more than 70 arrests under the Act in countries including Cambodia, Thailand and the Philippines, officials said.
Authorities wanted to bring the men back to the U.S. because they could face sentences of up to 30 years for each alleged victim, if convicted, said U.S. Attorney Thomas O'Brien.
"We believe that the sentences that they're going to be facing, should they be convicted in U.S. custody, are going to be severely stronger sentences," he said.
Jeffrey Blom, vice president of investigations for the rights group International Justice Mission, said he would rather see accused sex offenders face charges in this country, where the justice system is tougher.
Federal authorities in California have tried to crack down on U.S. citizens seeking sex overseas. Retired Marine captain Michael Joseph Pepe awaits sentencing for having sex with preteen girls while working as a teacher in Cambodia.
Some of the girls testified at his trial that Pepe drugged, bound, beat and raped them.