Crucial pieces of the evidence used to convict Canadian teacher Neil Bantleman of sexually assaulting young boys at a private school in Indonesia are seriously flawed, an investigation by the fifth estate has found.

"The things running through your head are: I'm Canadian, I'm a teacher, I'm going into a prison in Indonesia. Is this is a movie? Is this a nightmare?" Bantleman, 46, told the investigative program in Jakarta, in his first television interview.

Bantleman, a Burlington, Ont., native who used to teach at the Webber Academy in Calgary, was convicted and sentenced to 10 years in prison in April 2015 largely on the testimony of three kindergarten-age boys and little forensic evidence. His conviction was overturned last August, but his nightmare is far from over. The Indonesian justice ministry is determined to get Bantleman back behind bars and has filed an appeal of the most recent court decision. His passport has been revoked, leaving him stuck in Indonesia.

Herpes test key for case

The original allegations against Bantleman were made in March 2014 while he was teaching at the Jakarta International School (JIS), an upscale private school attended by children of diplomats, expatriates and wealthy Indonesians, and accused him and an Indonesian teaching assistant of sexually assaulting three kindergarten pupils some time between January 2013 and March 2014.

Perhaps the most emotionally compelling pieces of evidence in the case were lab reports that seemed to prove one of the alleged victims, a five-year-old boy, had contracted herpes.

The boy's mother, who goes by the name Pipit, had her son tested for the herpes virus a total of four times over a period of 19 months. She brandished one of those tests at a news conference in April 2014, insisting the test showed her son had tested positive for herpes. The results of the tests were entered into evidence in the case against Bantleman.

Bantleman is represented by one of Indonesia’s most celebrated lawyers, Hotman Paris, above, but even he is doubtful that Bantleman will win his case. (CBC)

The fifth estate tracked down the boy's family at an undisclosed location in Europe.

"Yes, I believe my son was sexually assaulted by Neil Bantleman," Pipit told host Mark Kelley in an exclusive interview.

Pipit says doctors told her that her son could only have contracted the herpes virus by sexual intercourse.

Toronto specialist contradicts herpes findings

The fifth estate obtained copies of all four lab reports from Pipit and showed them to Toronto-based infectious disease specialist Dr. Sumon Chakrabarti.

Beyond a reasonable doubt, this child has not ever been exposed to herpes. - Sumon Chakrabarti, infectious disease specialist

"Beyond a reasonable doubt, this child has not ever been exposed to herpes," Chakrabarti told the fifth estate.

The first two lab reports from hospitals in Indonesia indicated a positive result for what is called an IgM test.

The IgM test determines a patient's possible recent exposure to the herpes virus. But because of its high rate of false positives, the IgM test has been discontinued in most developed countries, including Canada.

Indonesian teaching assistant Ferdinand Tjiong kisses his wife outside a Jakarta court in April 2015. Tjiong and Bantleman were sentenced to 10 years in jail each that month after a four-month trial that critics say was fraught with irregularities. Their convictions were later overturned. (Darren Whiteside/Reuters)

A majority of infectious disease experts concur that another test, called IgG — which determines a patient's latent exposure to herpes — is the most accurate way to tell if someone is carrying the herpes virus.

The IgG test results on the first two lab reports of the boy were negative, and according to Chakrabarti, two subsequent tests, done approximately a year apart, also showed negative IgG results for herpes.

To clear up any remaining confusion, the fifth estate — with his mother's permission — had the boy undergo a final test for herpes at a reputable European laboratory. The results were definitive.

"This test is actually saying that herpes is negative," Chakrabati said, referring to the most recent test result. "The child has not been exposed to herpes."

But Pipit insists that the European experts got it wrong and she maintains her son does have the herpes virus.

Magic stones and potions

On June 13, 2014, police raided the Jakarta International School, combing the building looking for clues.

Pipit's son alleged he was attacked in a secret room near the staff lounge. He also said Bantleman used a magic stone and a blue potion to numb him before the assaults.

The fifth estate obtained a tape of the police search in the staff lounge. After extensive raids of the room, police found no evidence of a magic stone, a blue potion or secret room in the lounge. They did, however, find a blender that they claim was used to mix the potion. They found no DNA, fingerprints or witnesses to prove the boys were in the teacher's lounge.

Tracy Bantleman looks through some of the cards and letters of support her husband received at their house in Jakarta. There has also been a large outpouring of anger against the Canadian, however, within Indonesia itself. (Courtesy of Tracy Bantleman)

After Bantleman's conviction, he and fellow accused Ferdinand Tjiong, a teaching assistant at JIS, were sent to Indonesia's Cipinang maximum security prison to serve their respective 10-year sentences.

Bantleman told the fifth estate about his time in prison.

"When I first arrived in Cipinang, I said to our cell leader, 'I am not guilty,'" Bantleman said. "And he's like, 'It doesn't matter.' And I remember his words, because he was right. 'Once you get to that point, you're guilty, so what are you going to do about it?' is what he said.

"When you go into the cell, there's seven or eight other guys in there, and you don't know what to do, where to sit, who to talk to, if you're going to make it that night. I mean you're going in with allegations that you abused children, this is the worst allegation that you can go into prison with. This is where you hear that, this is where you get your justice, or the street justice as they say, so yeah, we're terrified."

'We weren't getting the support we needed'

Meanwhile, Bantleman's wife, Tracy, was concerned that his case was not getting the attention it deserved from the Canadian government.

"I believe it was the U.S. embassy, the British embassy and the Australian embassy made a statement of concern, and the Canadian embassy didn't. And that's why we felt that we weren't getting the support we needed from the Canadian government right from the beginning."

Along with Bantleman, right, and Tjiong, left, six cleaners at the Jakarta Indonesian School were also implicated in the sex-assault allegations. One of the cleaners died while in police custody and the other five were convicted and sentenced to up to eight years in jail. (Darren Whiteside/Reuters)

In August 2015, the Indonesian High Court overturned the convictions of Bantleman and Tjiong, and both were acquitted. The court dismissed the testimony of the young children and found contradictions in the medical evidence.

The case is far from over, however.

Prosecutor Sarjono Turin and his staff are busy preparing their appeal, which if successful, would send Bantleman back to prison to finish serving his 10-year sentence.

Turin says public opinion was a factor in deciding to appeal his acquittal, but he's confident he can make the case to convict the Canadian.

"If we weren't convinced, we would not have brought this case to the courts," Turin said. "Because we had that [certainty], it was our duty to protect the interests of the country and society to bring this case to the courts. "

I told Neil that based on past experience, you know, anything could happen. - Hotman Paris, defence lawyer

Even Bantleman's defence lawyer, Hotman Paris, thinks that given the outpouring of public anger around this case, it's doubtful Bantleman can win.

"I told Neil that based on past experience, you know, anything could happen," Paris said. "So, just prepare yourself. That's all I could say. And he knows that. So, he's ready for anything."

Others swept up in allegations

Six cleaners at the Jakarta International School were also the targets of sex assault allegations involving one of the three boys in Bantleman's case. Five men and one woman were arrested and beaten into confessing to sexually assaulting the six-year-old boy.

Tracy Bantleman feels her husband did not get adequate support from the Canadian government while incarcerated. (Faiz Mercury and David Allinson)

One of the cleaners, a 27-year old named Azwar wouldn't make it through the night. Within 24 hours of his arrest, he was pronounced dead. Police say he committed suicide by drinking bleach in the bathroom, but a photo obtained by the fifth estate suggests that might not be the full story. It shows his face was badly bruised and battered and still swollen after death.

With confessions in hand, convictions were now inevitable: the four men were sentenced to eight years in prison each, and the woman got seven years as an accomplice.

Meanwhile, Bantleman and Tjiong await their fates.

"I guess we look towards the future with positivity and anticipation of being able to touch back down on Canadian soil and seeing our parents and celebrating truth and justice and freedom," Tracy Bantleman said.