One of three women who claim they fell victim to a violent voyeur they met online asked police on Monday to arrest him.
She was with Pavena Hongsakul, founder of the Pavena Foundation for Children and Women.
The man, according to Ms Pavena, is a 33-year-old American and alleged former military serviceman. He told each victim he wanted to start a family with them in the United States.
After the victims fell for his lies and began a relationship with him, he secretly taped their sexual encounters. One woman who ended up marrying him said she was assaulted and blackmailed after filing for a divorce.
All three alleged that the man was a member of a secret group that exchanged and traded explicit videos and images. The victims remained silent initially out of fear he might share clips of them online.
According to the victims, the man had previously been married to a woman from the Philippines and a Chinese-American woman and was violent. They said he used dating apps to meet and chat with women.
Ms Pavena said she believes there are more victims who are scared of coming forward and encouraged them to contact the Pavena Foundation to seek help.
Police said the man has entered and exited Thailand multiple times on a tourist visa. A search warrant and a warrant for his arrest are being processed, and the RTP has coordinated with the Immigration Bureau to stop him leaving the country.