Neil Bantleman, the former Calgary teacher who seemed to be making up ground in his battle with the Indonesian justice system, has now been sent back to jail.

The country's Supreme Court overturned the acquittals of Bantleman and Ferdinant Tijong, an Indonesian teaching assistant, and ordered the pair to serve longer prison terms for the sexual abuse of three students at the Jakarta International School where they worked.

They were sentenced to 10 years for the crime in 2015, but they were able to successfully appeal to a higher court, and were acquitted in August.

Now, a three-member Supreme Court panel re-instated the convictions and ordered an 11 year sentence and a $7,440 fine.

"The judge panel concluded that the defendants were proven to have violated the 2007 Child Protection Law," said Suhadi, a spokesman for the panel, who uses a single name. "It did not only reinstate the District Court's verdict but also lengthened the sentence to 11 years."

The family of a Canadian schoolteacher say they're "completely stunned" after the Indonesian Supreme Court overturned the acquittal of Neil Bantleman and sentenced him to 11 years in prison.

Guy Bantleman, Neil's brother, said Thursday morning that heading into the verdict the family felt confident in the outcome.

"This came completely out of left field," Guy Bantleman told CTV's Canada AM from his home in Burlington, Ont.

The Canadian government has also shown their outrage at the ruling, with Foreign Affairs Minister Stephane Dion calling it unjust.

He went on to say in a statement that the case was not handled in a fair and transparent manner and the outcome has serious implications for Indonesia's reputation as a safe place for Canadians to work.

Dion said Canada would continue to raise the case of Bantleman at the highest levels while Canadian officials continue to provide consular assistance to Bantleman.

Chandra Saptaji, head of the general crime section at the South Jakarta Prosecutors' Office, said Tijong was taken from his house early in the day and was now serving his sentence at the Cipinang Prison in eastern Jakarta.

"We are still looking for Bantleman, who is actually under a ban to leave the country," Saptaji said. "Hopefully, he is co-operative and complying with Indonesia law."

The Jakarta International School, now known as the Jakarta Intercultural School, is for the children of foreign diplomats, expatriates and Indonesia's elite. It has 2,400 students aged three to 18 from about 60 countries. The school's principal and a number of other teachers have said they believe Bantleman is innocent.

Last December, five janitors at the school who were arrested in the same case were sentenced to up to eight years in jail. Police said a sixth suspect in that group committed suicide.

Under Indonesian law, both Bantleman and Tijong still could challenge the sentence by filing for judicial review by the Supreme Court if they have new evidence.

(With files from the Canadian Press and the Associated Press)