Ubon Ratchathani, Thailand: Police have detained a Sydney man jailed in 2012 over the rape and molestation of Indonesian boys as young as eight who was found teaching at a school in north-eastern Thailand.
Fairfax Media witnessed police confronting Peter Dundas Walbran, a former head of the Australian International School in Jakarta, with a warrant to search his apartment on suspicion of possessing child pornography as he was leaving to go to school on Wednesday.
Walbran lashed out at Fairfax Media, attempting to push a camera away, after an Australian Federal Police agent and Thai police escorted him from his apartment. He refused to answer questions and glared angrily at a small group of journalists. 
He was last night being detained in immigration department cells. Police released an 18-year-old Thai man who had been living with Walbran after several hours of questioning.
A police investigator said they had seen Walbran with children from his local neighbourhood several times since Monday.
"We saw Walbran take a boy from the apartment to a shop on [the] back of his motorbike," the investigator told Fairfax Media. "We are investigating."
Walbran is expected to be flown to the capital Bangkok as investigations continue into his activities in Thailand.
How Walbran came to be again teaching children in Asia after being deported from Indonesia to Australia last year raises questions about the effectiveness of Australia's National Child Offender Register.
Melbourne investigator Glen Hulley tracked Walbran, 59, to an international school in Ubon Ratchathani, 630 kilometres from Bangkok, where he has been teaching children aged 12 to 17 for eight months.
Photographs on the school's Facebook page show children prostrate on the ground in front of Walbran and other teachers in a Thai ritual where students pay respect to their teachers. Walbran was hired to work at the school despite the fact that a simple Google search would have shown him to be a convicted paedophile.
The revelation has stunned teachers at the Narinukun international school, who worry about the impact it will have on students. They fear the school will collapse if furious parents withdraw their children.
A police undercover operation kept Walbran under surveillance for days, including from an apartment adjacent to one he had been renting for months.
Fairfax Media withheld publishing details of Walbran's past crimes until police swooped on his apartment on Wednesday.
Police raided the apartment two days after new legislation came into force in Thailand that criminalises possession of child abuse material, with offenders facing up to 10 years jail.
Fairfax Media can reveal that Thai authorities will deport Walbran on the grounds of bad character if investigators find he has not offended in Thailand.
Walbran was sentenced to three years jail on the Indonesian island of Lombok in 2012 for offences that shocked investigators, including the repeated rape and abuse of children.
Edi Setiawan, an Indonesian child sex investigator, told Fairfax Media that six children have told him Walbran abused them on Lombok but only three were prepared to give police statements.
Mr Setiawan said that even after being deported to Australia, Walbran emailed one of his victims saying he planned to live in Thailand but would return to Lombok to see him. Mr Setiawan said Walbran offered one of his victims a house and another a motorbike, but they agreed to testify against him after he reneged on the promises.
Walbran was suspended in   March 2007 from the exclusive Australian International School in Jakarta after police began investigating him for child sex offences outside of the school.
Walbran returned to Australia before the investigations were complete and was living at Warriewood, on Sydney's northern beaches, when he was extradited to Indonesia in   October 2011, following a request from Jakarta's Law and Human Rights Ministry. Walbran served just over two years of the three-year jail sentence on Lombok before being deported to Australia in   April last year. Mr Setiawan said he visited Walbran in jail two days before his deportation. "He looked angry and kept telling me he was innocent," he said.
Two weeks after arriving back in Sydney on temporary Australian travel documents, Walbran was served papers ordering him to register his Indonesian convictions with Australia's National Child Offender Register. But he failed to do so and left Australia again early this year on a New Zealand passport he acquired while in NSW.
If Walbran had been on the child sex offender register he would have been required to report his intended travel and Australian Federal Police would have alerted Thai authorities to his arrival in the country.
The Narinukun school cancelled Walbran's work contract on Wednesday.