neil bantleman
Bantleman is led away after first being found guilty in April, 2015Getty

A Canadian teacher was in custody today (26 February) after surrendering to authorities in Indonesia after the country's Supreme Court overruled his acquittal and that of an Indonesian teacher on charges that they sexually abused pupils at a prestigious international school in Jakarta.

Neil Bantleman and Ferdinand Tjiong were sentenced to ten years in prison last April by the South Jakarta District Court. They then appealed to the High Court, which acquitted them in August, ruling there was insufficient evidence to convict them.

Along with the overruling, the court increased the men's prison sentence to 11 years.

Bantleman and Tjiong were both teachers at the Jakarta International School before they were arrested in 2014 on child sex abuse charges.

Four male janitors were already serving eight-year sentences for the attack. A woman was also serving seven years for being an accomplice. A sixth suspect committed suicide in custody by drinking bathroom cleaner, according to police.

Bantleman flew back to Jakarta escorted by embassy officials. The South Jakarta Prosecutors' Office said that he was being co-operative.

Meanwhile, Canada's Foreign Affairs Minister, Stephane Dion, described his dismay at the decision: "This decision is unjust, given the many grave irregularities throughout the various proceedings in this case and the fact that all evidence presented by the defence has systematically been rejected."

"Mr Bantleman and Mr Tjiong were not provided the opportunity to demonstrate their innocence. Despite Canada's repeated calls for due process, this case was not handled in a fair and transparent manner."

Jakarta International School is now called Jakarta Intercultural School and is mostly attended by the children of diplomats, expatriates and the Indonesian elite.

The teachers were also ordered to pay a fine of £5,300 ($7,440) or spend six more months in prison. Bantleman and Tjiong still have the ability to challenge the ruling by filing the Supreme Court for a judicial review.