According to police, the incident had recently taken place and the girl had been locked up in a room by her family to "drive away evil spirits". The tantrik identified as Suresh Cherry allegedly branded the girl with a hot rod. Neighbours, who had later noticed this, alerted the police.
The Pithapuram police arrested priest Cherry last night, while the girl's parents - Kameswara and Sunita -- had been taken into custody on January 21, police said.
According to police, the girl is undergoing treatment at Pithapuram Government General hospital.
Further investigation is on, police said.