The CBI has taken over the investigation into alleged sexual harassment of a woman in Pollachi town of Tamil Nadu's Coimbatore district by a gang of men who had shot a video of her and blackmailed her demanding money, officials said.
The agency has registered two FIRs in the matter -- one pertaining to sexual harassment of the woman and second related to an assault on her brother -- against different sets of the accused, they said.
The CBI has begun the probe on the request of the Tamil Nadu government on March 12.
The gang is believed to have sexually harassed and blackmailed a large number of women in Tamil Nadu which triggered an outrage in the state.
Citing the need for specialised attention, dedicated investigation with technical expertise and the extremely serious nature of the crime, the government had given its consent transferring the harassment and a related assault case from the state's CB-CID to the CBI.
A gang of four men had on February 12 allegedly tried to strip the woman inside a car near Pollachi, over 500 km from Chennai, and had shot a video of the act and blackmailed her using the visuals.
The victim, who managed to free herself, lodged a complaint with police on February 24.
The case assumed political overtones since a local functionary of the ruling AIADMK allegedly attacked the victim's brother.
The attack by the functionary, who was later expelled from the AIADMK, coupled with reports in a section of media that the gang had sexually harassed several other women, led to an outrage.
The issue eventually snowballed into a political row and the main opposition DMK targeted the AIADMK asking if it was protecting the accused persons.
A slew of protest demonstrations by parties including the DMK, students and the youth outfits had escalated the row, bringing more pressure on the government and police for speedy action.
More visuals of the gang have surfaced on social media, heightening suspicion about them among the people, Coimbatore district police had said.
The four accused in the sexual harassment case -- Sabarirajan, Thirunavakkarasu, Sathish and Vasanthkumar -- are under judicial custody. They were booked under various sections of the IPC, Tamil Nadu Prohibition of Harassment of Women Act and the Goondas Act.
Nagaraj, the expelled AIADMK functionary, is one of the accused in the assault case besides Senthil, Babu, Manivannan and Vasanthakumar.
The CBI has taken over these FIRs and re-registered them as its cases which is part of a procedure.