Canadian teacher Neil Bantleman is back in police custody in Indonesia after that country's Supreme Court overturned his acquittal on charges of sexually abusing children at a private school.

The court has ordered the Burlington, Ont., native returned to jail, and he surrendered to police Thursday, according to his brother Guy.

"Neil is back in Jakarta," Guy Bantleman said. "He is in police custody … being processed by embassy officials, his lawyers and the prosecutor," he said.

Bantleman will spend the night at the prosecutor's office.

The man's brother said the entire family is frustrated by the process and has little faith in the judicial system. He told CBC the family plans to ask for a judicial review and to introduce new evidence, including information from a CBC fifth estate report on the case.

He was elated after Christmas … this has sent him in a new direction. - Guy Bantleman

"We thought we were heading in the right direction," Bantleman said.

The family says it will be putting more resources toward the case and hoping that diplomatic pressure from the Canadian government would help his case.

Will rights be respected?

The family is encouraged by the strong words coming from new Liberal government. Stéphane Dion, Canada's minister of foreign affairs, said in a statement that the government was "deeply dismayed" by what it called an "unjust decision."

In a scrum Thursday afternoon, he went further.

Dion suggested the lack of due process sends a wider message about the country to the international community.

"I just want to say that already today Indonesia is penalizing itself because the confidence one may have about the ability to do business in Indonesia, to have justice in Indonesia, has been jeopardized by the decision of the Supreme Court yesterday," he told reporters.

"So if Indonesia want to send a message that your rights will be respected — you will have due process in Indonesia — they need to correct the situation for Mr. Bantleman and the other gentleman."

The decision "came out of left field," Guy said in an interview with CBC News Network.

"It is astonishing this happened at such a high level," he said from his home in Burlington.

Guy Bantleman said his brother is "devastated" and "says he can't go back to jail. He was elated after Christmas … this has sent him in a new direction."

Bantleman was outside Jakarta, visiting another area in Indonesia when the decision was made, Guy told CBC.

Indonesian teaching assistant Ferdinand Tjiong also had his original conviction restored.

Sentence lengthened

Neil Bantleman and his wife, Tracy, also a teacher, had travelled to the country together for job opportunities at Jakarta International School, an upscale private school with about 2,400 students.

Bantleman, 46, was accused of assaulting three kindergarten-aged boys between January 2013 and March 2014.

Bantleman and Tijong were originally sentenced to 10 years in prison. The decisions were overturned by the Jakarta High Court in August 2015.

However, Bantleman's passport was revoked and he was not allowed to leave the country pending the government's appeal.

Supreme Court spokesman Suhadi said a three-member judge panel made the decision Thursday, adding an additional year on to their sentences.

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

Bantleman and Tijong were also fined the equivalent of $7,440 Cdn each.

Diplomatic hopes

Guy Bantleman told CBC Hamilton he will have a meeting with officials in Ottawa later Thursday, with a trip planned to the capital in the coming days.

Guy Bantleman talks carefully about the case and illuminates some troubling issues with the haste with which Neil's acquittal has been overturned 7:34

When asked how his brother is handling the order issuing him back to jail, Bantleman said he was "fragile" at the idea of going back to prison: "He's been able to process this and understands it's what he has to do."

His brother feels it's only the beginning. "It took a lot of time to get here," Bantleman said. "The diplomatic effort will be what resolves this in the end."

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

Bantleman said "we didn't think we'd have to get to that level."

Indonesian returned to prison

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

Evidence used to convict Canadian teacher of sexually assaulting young boys in Indonesia seriously flawed, investigation finds 2:54

In an interview with CBC's the fifth estate, Neil Bantleman recounted the stunning day when he was jailed.

"I'm going into a prison, it's one in the morning. Is this a movie? Is this a nightmare?" he said.

The school has supported Bantleman and Tijong throughout the legal process.

"We are shocked and devastated by this latest development," admissions officer Jennete Felina said on behalf of the school to CBC by phone on Thursday. "The claims against Neil and Ferdi are baseless and without evidence. We have faith that a judicial review will bring justice."

The convictions occurred despite a lack of witnesses, with allegations Bantleman committed the assaults during the school day in his office, which is a clear glass structure.

Allegations that one of the children contracted herpes from the alleged assault were not supported by independent testing in Europe, the fifth estate found.

Four male janitors at the school were already sentenced to eight years in prison in that case and a woman received a seven-year prison sentence as an accomplice. Police said a sixth suspect killed himself in custody by drinking bathroom cleaner.

The South Jakarta District Court threw out a civil lawsuit in which one child's parents sought $125 million from the school for alleged negligence.