Interpol has identified a suspected serial paedophile being hunted across Asia as Christopher Paul Neil.
Mr Neil, who was born in 1975, is a Canadian now believed to be in hiding in Bangkok.
Panaspong Sirawongse of Interpol in Thailand said he had taught at an international school in the Thai capital in 2003-04.
Thai immigration, crime suppression and child crime police are hunting for the man, who entered the country last week from South Korea after Interpol posted unscrambled pictures of his face on the web.
Keo Vanthan, deputy director of Interpol in neighbouring Cambodia, where police say Neil was photographed sexually abusing small boys, said border authorities had been alerted in case he tried to sneak out of Thailand by land.
Detectives have been trying to track the suspected paedophile since German police discovered photographs on the Internet three years ago showing him raping 12 boys in Vietnam and Cambodia.
His face was disguised in different ways, but experts at Germany's BKA federal crime office managed to unravel the images to reveal a white man with receding black hair.
When Interpol posted the cleaned-up picture of the suspect on its website - the first time it has issued a direct worldwide appeal - more than 350 people came forward.
Mr Neil, who had thus far been known only by the codename 'Vico', was identified by information from five sources on three different continents, the international police body said.
Yesterday, it released an image taken by security cameras at Bangkok airport last Thursday when Mr Neil flew in from Seoul, where he had also been teaching.
