Canadian teacher Neil Bantleman and Indonesian teaching assistant Ferdinand Tjiong get 11-year jail term
Canadian teacher Neil Bantleman (L) waves beside Indonesian teaching assistant Ferdinand Tjiong to students as they wait inside a holding cell before their trial at a South Jakarta court, Indonesia, April 2, 2015 Reuters

Canada expressed "shock and dismay" over the Indonesian supreme court's decision to reinstate a 10-year prison term for Neil Bantleman, who was accused of sodomising students at a top Jakarta school.

Canada's Foreign Affairs Minister Stephane Dion said there were many "grave irregularities" in the case and that the government was "deeply dismayed and shocked" by the verdict.

"Despite Canada's repeated calls for due process, this case was not handled in a fair and transparent manner. The outcome of this case has serious implications for Indonesia's reputation as a safe place for Canadians to work, travel and invest as well as for its long history of cooperation with Indonesia," the minister said, according to Sydney Morning Herald.

Earlier, US Ambassador to Indonesia Robert Blake had said he was "shocked and disappointed" after the top court overturned an appeals court verdict acquitting the Canadian.

"In August 2015, the Indonesian High Court found that there was not sufficient evidence to support the teachers' conviction," Blake said.

"It is not clear what evidence the Supreme Court used to overturn the High Court's decision. The outcome of the legal process will impact international views about the rule of law in Indonesia," the ambassador added.

Under the supreme court's verdict, Canadian national Neil Bantleman and Indonesian teaching assistant Ferdinand Tjiong will have to serve a new 11-year sentence after they were found guilty of sexually abusing three young children.

The two teachers had been convicted of sexually abusing students at Jakarta International School and they were awarded a 10-year sentence. However, they were acquitted in August 2015.

"They have been sentenced again to 11 years," Supreme Court spokesman Suhadi told Reuters on Thursday.

The men were arrested in July 2014 after parents of a 6-year-old boy at the school alleged that he'd been sodomised.

Prosecutors said Bantleman was travelling in Bali when the Supreme Court announced its verdict. He flew back to Jakarta after the court's decision and is currently lodged in Cipinang prison.