Lawyers for a Canadian teacher serving a 10-year prison sentence in Indonesia have filed an appeal of his child sex abuse conviction.

Neil Bantleman, of Burlington, Ont., wants the Indonesian High Court to overturn his conviction on the grounds of insufficient evidence, a flawed investigation and biased judges. His representatives have also launched a US $125 million lawsuit against the Jakarta Intercultural School, where the alleged incident took place.

Bantleman, 45, and an Indonesian teaching assistant were charged last July with sexually abusing three children over the course of two years at the Jakarta Intercultural School where they worked. Both men maintained their innocence throughout a four-month trial that ended with guilty verdicts.

Bantleman's wife and brother loudly criticized the Indonesian court system throughout the trial. Bantleman's brother, Guy, says the lower court has a 97 per cent conviction rate. He accused the lower court of giving into public and media pressure in handing down the guilty verdicts.

"Until we get to the Supreme Court, we won't get a true hearing of all the evidence that was put forward," Guy Bantleman told CTV News Channel on Sunday.

He said he hopes the appeal will move swiftly through Indonesia's district court level to the High Court, where judges "seem to be a little bit more learned."

Guy Bantleman said he wants the High Court to look at his brother's case "in totality."

Neil Bantleman sent an open letter to Canadian Prime Minister Stephen Harper last month, asserting his innocence and calling for government intervention to help with his case.

In the letter, Bantleman said the court process was not fair or transparent, and that his human rights had been violated.

"I realize the government cannot interfere in the legal proceedings of another country and I do not expect the government to make strong statements against the workings of any other country's legal system," Bantleman wrote in the letter. "However, what I cannot understand is the unresponsiveness of the federal government with regards to my case."

Guy Bantleman says his brother is doing "OK" behind bars in Indonesia, where he will have to wait through the lengthy appeal process. "We're making sure that he's safe and he's provided for," Guy said.

Neil Bantleman moved to Indonesia with his wife four years ago. The two taught at the Jakarta Intercultural School, where they worked with the children of foreign diplomats and Indonesia's elite.

Bantleman's defence lawyers say they will be filing an appeal for the teaching assistant who was also convicted in the case.