Tamil daily, Makkal Osai, said the teacher had been doing this for several months.
Nine pupils have been identified to have been his victims, according to the report.
It came to light two weeks ago when a Year Five pupil reported the alleged misconduct to another teacher.
The headmaster was reported to have informed the district education office.
The report said the parents and parent-teacher association were furious they had not been informed of the incidents and fear a cover-up.