The wife of a Canadian teacher detained in Indonesia over allegations of sexual assault involving students is pleading for her husband’s release, calling the ordeal "a horrific nightmare."

Neil Bantleman, 45, has been held in the capital of Jakarta without charge for the past week. He had initially gone to police to be questioned as a witness in an investigation into allegations that three kindergarten students were assaulted at the Jakarta International School, according to local media reports. Bantleman works at the school as a learning co-ordinator, working with teachers and administrators to develop and implement the curriculum, according to his brother, Guy.

According to a report in the Jakarta Post, six cleaners hired via an outside company were arrested for allegedly raping a boy in a school bathroom earlier this year. Since then, the parents of two other students came forward, claiming that their sons were sexually assaulted by teachers.

Guy Bantleman said Monday that Neil had gone to local police for what was supposed to be routine questioning as a witness. After nine hours, he and teaching assistant Ferdinand Tjiong were detained.

The two men assumed that they would be released the next day after further questioning, Guy Bantleman told CTV Toronto. But a week later, they remain in custody without having been charged.

“I think he’s gone through a process of the utter surprise and shock and being fearful to start, being in a prison in a foreign country,” Guy Bantleman said of his brother. “As the week has gone on, he’s definitely become more resolute.”

Neil’s wife, Tracy, who teaches at the school, said last week that her husband is “innocent.” She told The Canadian Press Monday that the family has faith in the Indonesian legal system, but is hoping Canadian consular officials will step up efforts to secure his release.

Guy Bantleman said Canadian consular officials in Indonesia have been working with his brother and the family appreciates their efforts. However, the family would like Foreign Affairs Minister John Baird to put more pressure on police to move Neil’s case forward so he can clear his name.

A spokesperson for the Department of Foreign Affairs would not name Bantleman in a statement about the case provided to CTV News Monday afternoon.

"Canadian consular officials are providing assistance to a Canadian citizen who has been detained in Indonesia. Consular officials are engaged with local authorities to gather additional information," the statement read.

"To protect the private and personal information of the individual concerned, further details on this case cannot be released."

Under Indonesian law, Bantleman can be held for 20 days without charge and other 20 days without a judicial review.

"This isn’t about getting Neil released and just walking away. This is about co-operating and getting this issue resolved because at the end of the day, it’s still my brother’s reputation," Guy Bantleman said.

"He needs to be exonerated from these charges to make sure that his life can go on as normally as it can be given the circumstances."

Indonesian officials have confiscated Bantleman’s passport, and he would abide by any rules of his release while the case proceeds, his brother said.

But because his brother did not have direct, daily contact with the students, he knows very little that could help investigators, Guy said.

"He really doesn’t know anything. That’s the challenge," he said.

"He doesn’t know these kids, he hadn’t had exposure to these kids prior to this case starting."

The Jakarta International School was founded by the Australian, American and British embassies to serve children of diplomats and other expatriates.

The three embassies issued a joint statement last week, saying they are “deeply concerned about the detention of several JIS teachers.”

"We believe JIS and its teachers have closely co-operated with police authorities, and we are surprised at these developments given the presumption of innocence in Indonesian law," the statement read.