The brother of teacher Neil Bantleman of Burlington, Ont., says in an email to The Canadian Press that family and supporters of the accused Canadian were "devastated" to hear the decision Tuesday in the South Jakarta District Court.
In a letter filed with the court last week, Neil Bantleman had said the allegations in the indictment against him were "baseless and completely false" and asked for the case to be dismissed.
He said the indictment fails to comply with Indonesian law and should be "rendered null and void.''
Bantleman and teaching assistant Ferdinant Tjiong, who have been in custody since July, are being tried separately.
Guy Bantleman, the brother of the accused teacher, says in his email: "Today, the judges ruled that the indictment written by the public prosecutor was determined to be legally valid."
"The judges did not speak to the merits of the case," he added.
"The exception filed by our lawyers was rejected in its entirety," he said, referring to what is known as an application for exception that was submitted by Neil Bantleman and his defence team last week.
Reports say an application for exception seeks a ruling from the court that a case should be thrown out. The prosecutor in the case presented briefs Thursday in opposition to the application.
"While exceptions are rarely granted, the baseless indictment that noted a law that now does not exist, and is vague in its accusations, we felt was another strong argument for the case to be dismissed," Guy Bantleman's email said.
Both Bantleman and Tjiong have maintained their innocence as do fellow teachers and the principal at the Jakarta International School. A judge read the charges against Tjiong and Bantleman in a Dec. 3 session but they were not required to enter a plea.
Five janitors at the school are being tried over the same allegations. A sixth died in custody.
Guy Bantleman said in his email that more than 100 parents, students and staff of the school were at the courthouse on Tuesday, adding that the court session was open and those on hand were able to sit in for it. Previous hearings in the case had been closed-door sessions.
Consular officials from both the Canadian and British embassies were present, he added.
Guy Bantleman has said while consular officials are providing assistance, the family also received a letter from the junior minister responsible for consular affairs, stating Ottawa won't pressure Indonesia to release his brother from jail.
Supporters of Bantleman and Tjiong say that one of the three students, who was six at the time the alleged abuse occurred, was subject to suggestive questioning by inexperienced police. The abuse was alleged to have happened at a room in the school during teaching hours.
Guy Bantleman said in his email that the prosecution requested more time to prepare its witnesses and that the request was granted by the judge. The prosecution is expected to present the alleged child victim's testimony by teleconference.
"We are disappointed but not disheartened. The trial will give us the opportunity to prove Neil and Ferdi are innocent," he said.
The family of one of the three students is suing the school for $130 million.
The school in southern Jakarta is attended by the children of foreign diplomats, businesspeople and Indonesia's elite.
Bantleman moved to Indonesia four years ago with his wife, who also teaches at the school.
Both Bantleman and Tjiong could face up to 15 years in prison if convicted.