The accused Suresh, who was arrested yesterday, used to take classes for students at a Sunday school attached to a Syrian Jacobite Church near Kothamangalam, about 50 kms from here.
Suresh, who is a neighbour of the 16-year-old victim, had allegedly sexually abused the boy since 2015 after threatening him. The victim also used to attend the Sunday school classes, they added.
The teacher has been charged with IPC Section 377, (Unnatural offences) and the Protection of Children from Sexual OffencesAct (POCSO Act), they said.
Three such incidents of sexual abuse have been narrated in the complaint lodged with the police, police said.