A 93-year-old Australian man facing pedophile charges in northern Thailand had planned well in advance to flee to Burma, including withdrawing funds from his bank account, legal sources said.
West Australian Karl Joseph Kraus, arrested on July 24 by Burmese officials in the city of Pa-an, the capital of Karen state, has a scheduled court appearance in Chiang Mai on Monday.
"It was a scheduled (court appearance) but things must have changed now that he has jumped bail," legal sources told AAP. They said Kraus had been planning for some time to flee Thailand, having taken steps to access his bank account.
Officials said Kraus had been living in rented accommodation for a month before Burmese officials doing a check of his documentation found he had entered Burma illegally.
But late on Sunday Kraus's whereabouts were uncertain after his arrest and being deported back to Thailand last Friday.
Kraus, who was born in Germany, was arrested in June 2010 and faces charges of sexual assault on four young sisters near his residence on the outskirts of the Thai northern city of Chiang Mai. Kraus had been teaching English to the village girls, one as young as five, when the alleged abuses began and continued over almost two years.
He was later released on bail of 400,000 baht ($A12,900).
Thai officials say they are concerned for Kraus's health and wellbeing if found guilty and sent to the local prison.
The Sydney Morning Herald reported that Kraus looked "frail and dishevelled" when he was handed over Tto hai immigration police last week.
During earlier detentions prior to being granted bail authorities had held Kraus at a local hospital rather than in a prison cell.