Bangkok: Interpol identified a suspected serial paedophile being hunted across Asia on Tuesday as Christopher Paul Neil, a Canadian born in 1975 and now believed to be in hiding in Bangkok.

Panaspong Sirawongse of Interpol's regional offices in Thailand said Neil, whose digitally swirled face in Internet photos was unscrambled by German police computer experts, had taught at an international school in Bangkok in 2003-04.

He did not give the school's name.

Thailand's immigration, crime suppression and child crime police divisions were involved in the hunt for Neil, who entered the country last week from South Korea after Interpol's unprecedented release of his picture, Panaspong said.

"They are also looking for children he abused and took photos with," he told Reuters. "There were three boys he had abused. One boy has been identified and is being sought, two others have not been identified."

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 across the border.

"We have issued an alert to all our international borders," although Cambodia did not yet have enough evidence to issue an arrest warrant, Keo Vanthan told Reuters.

Investigators have been trying to track down Neil for three years after German police discovered photographs on the Internet showing him raping 12 young boys in Vietnam and Cambodia.

His face was disguised with a swirly digital pattern, but experts at Germany's BKA federal crime office managed to unscramble it.

The cleaned-up images, showing a white man with receding black hair, were posted on Interpol's Web site (www.interpol.int) a week ago.