The girl was allegedly sexually assaulted and electrocuted last year at her home in Kurumbapatti village in Dindigul, police said, adding, one person had been arrested in connection with the incident.

He was acquitted recently. Law Minister C Ve Shanmugam described the alleged sexual assault and killing of the girl as "heinous", even as opposition DMK, PMK and the Congress demanded action.

With the victim being the daughter of a hair-dresser, nearly three lakh barber shops across the state downed shutters demanding justice for the 12-year-old victim. Shanmugam said there were reports that the accused has been acquitted (by a local Mahila court).

"A minor girl has been sexually assaulted and brutally murdered. This is a heinous crime. The government will look into the matter and take all immediate steps to go for an appeal," he told reporters at Gingee in Villupuram. DMK president M K Stalin, in a tweet, accused the prosecution of not properly placing the evidence in the case, leading to the acquittal of the accused.

"Appeal (in the interest of) justice" for the victim, he tweeted. Congress MPs from Dindigul and Karur, P Velusamy and S Jothimani, respectively, and DMK legislator R Sakkarapani submitted a petition with Dindigul Collector M Vijayalakshmi, urging the government to file an appeal in the case.

PMK founder Dr S Ramadoss, whose party is an ally of the ruling AIADMK in the state, expressed shock over the acquittal and demanded that the state government file an appeal and ensure stringent punishment for the culprit.