The now pregnant teacher, who had been missing along with the boy since March 31, 2015, was arrested after both were traced to a private mill near Tirupur where they were working, police said today.
The boy's parents in their complaint to police last year, had said he had taken away 60 sovereigns gold jewels and Rs 10,000 cash from his house before fleeing with the teacher.
The teacher and the boy had eloped on the final day of the class X exams.
The post-graduate teacher had been booked for kidnap and sexual assault under relevant sections of the IPC and Protection of Children from Sexual Offences (POCSO) Act.
After a medical check up at a government hospital, the teacher of a school in Kadayanallur in the district was produced before Judicial Magistrate Jagadeeswari who remanded her to judicial custody yesterday, they said.
The boy was sent to a children's home and would be produced before the Madurai Bench of the Madras High Court on Monday where a habeas corpus petition by his parents is pending.