Neil Bantleman, a learning co-ordinator at the Jakarta International School, was arrested in connection with allegations that several kindergarten students at the school were sexually assaulted.
The 45-year-old teacher, originally from Burlington, Ont. and who spent time teaching in Calgary, has been held in a Jakarta jail since July 14 but hasn't been charged with any crime.
In a letter addressed to Minister of Foreign Affairs John Baird and Minister of State for Foreign and Consular Affairs Lynne Yelich this week, his brother guy asked the government to "emphasize the seriousness of which Canada perceives the situation."
"By no means do I expect the Canadian government to interfere with the legal process of an independent country, but I would request the Canadian Government issue a statement simply stating that a Canadian citizen has been held for 100 days and the Canadian government urges Indonesian officials to produce the evidence that justifies his continued detention, or release him," he wrote in the letter, which was posted to the Facebook group Free Neil Bantleman & Ferdi Tjiong.
If the government can't do so, Guy said he would also like an explanation.
When asked about the Bantleman family's latest letter, the Department of Foreign Affairs, Trade and Development did not name Bantleman, but said Canadian consular officials are providing assistance to a Canadian citizen who has been detained in Indonesia.
"Consular officials remain engaged with local authorities on this case," a spokesperson said in an email to CBC News.
The department did not provide further details citing privacy concerns.
Bantleman's arrest stems from an investigation by Jakarta police into sexual assault at the school earlier in 2014, which has since received international coverage. The Jakarta Post newspaper reported that six janitors were arrested for allegedly raping a young boy in a school bathroom in March.
Later, the parents of two other students filed police reports claiming their sons were sexually assaulted by teachers. The newspaper also reported that one complainant, whose family is suing the school for $125 million US, implicated teachers at the school.
In July, Bantleman and Ferdinand Tjiong, an Indonesian teaching assistant, were detained and questioned by police for nine hours. They were never released
Bantleman's passport is being held by police, and his home and office have been searched by investigators.
Since his arrest in July, Bantleman's detention has been extended multiple times. The first time was in August, when it was extended for 40 days, and again for 30 days in September. Last week, the family learned that the detention was extended for another month.
The latest extension means Bantleman could be behind bars for a total of 120 days, the maximum time allowed under Indonesian law before charges must be laid.
"The last three months have been a nightmare, and we are eagerly awaiting the day that Neil is released, and ultimately the moment he is back in Canada," Guy wrote in his letter.