Department of Special Investigation Lt. Col. Paisith Sungkahapong said the U.S. Department of Homeland Security informed the Thai agency in November that images were being uploaded and sent from a specific Internet address. The uploads were traced by The National Center for Missing and Exploited Children, a non-profit group funded by the U.S. government.
Police arrested Fabian Frederick Blandford, 64, at his home in Chiang Mai province, where he lives with his Thai wife and two children.
He said that according to an initial investigation, Blandford was friendly with his Thai neighbors. Police said he offered to teach English to local children. Thai newspapers said he had once been a Buddhist monk.
Blandford is being held pending formal charges. Under a Thai law that came into force last month, possession of child pornography carries a penalty of up to five years in prison, and distribution of the images carries a penalty of seven years.
A 67-year-old American, James Craig Neumann, was arrested on similar charges last month in a different district of Chiang Mai. He was described as a former English-language teacher.
DSI's Paisith said the Department of Homeland Security notified Thai authorities of at least one other pedophile-related case last year, involving a Thai man who was traced after posting obscene photos of young girls to a pedophile website. The man had been a primary school teacher.