Paul Cornelius Jones, 39, who has lived in Thailand for seven years, was arrested after police raided his Bangkok apartment and found a computer containing photos of naked boys and girls, said police Col. Apichart Suribunya, head of Thailand's liaison office for Interpol, the international police agency.
Thai police acted on a tip-off from their British counterparts, who told them Jones had been sending photos of naked children to Britain over the Internet, Apichart said.
Police said Jones has been working as a teacher at a Bangkok private school.
Jones, of Cardiff, Wales, has been charged with distributing pornographic photographs of children under age 15, which carries a maximum penalty of 15 years in prison, Apichart said.
Another officer in the Thai Interpol office, Maj. Phongphon Iamwicharn, said that Jones did not appear in the photos, and that there was evidence he had sold the pictures.
Thai police arrested Christopher Paul Neil of Canada on Oct. 19 on charges of having sex with several young Asian boys after Interpol issued an unprecedented worldwide appeal to identify and apprehend him.
Interpol began its manhunt after finding about 200 pictures on the Internet of Thai, Cambodian and Vietnamese boys being sexually abused by a man whose face was digitally obscured.
After German police computer experts unscrambled the photos so the man's face was recognizable, Interpol circulated them publicly. Tip-offs led them to identify Neil as a suspect.
He has been charged with child sexual abuse, but police are still investigating the case.
Neil has also worked as a teacher at schools in Thailand, South Korea and Vietnam.
Jones and Neil are both in Thai police custody.
Several Southeast Asian countries are popular among pedophiles and sex abusers because of poverty that drives children and their parents to accept money for sexual favors, and sometimes because of lax law enforcement.