The criminal court in Bangkok, the Thai capital, had handed down a sentence of six years and six months, but the judge halved the sentence, citing Neil's guilty plea.

Neil is set to face another trial in October on a charge of molesting the boy's younger brother, who was nine at the time of the alleged offence.

Neil was arrested in Thailand in October 2007 after computer experts in Germany reconstructed a series of "swirled" internet images and Interpol issued a worldwide public appeal to identify him.

Following the Interpol appeal, Neil fled to Thailand from South Korea, where he had been teaching, but was arrested 11 days later by Thai police.