The police have arrested four men in the molestation cases.
The Tamil Nadu Crime Branch CID Wednesday took over the investigation into the case of sexual harassment of a 19-year old woman in nearby Pollachi, which has drawn public outrage.
CB-CID IGP Sridhar and the special officer Nisha Parthiban held discussions with Superintendent of Police R Pandiarajan and other senior officials and received all documents related to the case.
Talking to reporters, Mr Sridhar said CB-CID would seek custody of the four accused, now in judicial custody, for interrogation as part of investigation in the case, which had drawn outrage.
The special teams will review the documents provided by the local police and the investigation will cover all the aspects, he said.
Assuring a fair and transparent investigation, the IGP said efforts would be made to complete the investigation at the earliest.
Four people, including key accused Thirunavakkarasu, were arrested late last month in connection with the case which sent shock waves after a leaked video in which the woman was screaming and resisting her assailants went viral.
There were also reports that the four had indulged in similar sexual harassment of several other women over the past seven years after befriending them.
The case assumed political overtones after a local functionary of ruling AIADMK allegedly attacked the victim's brother for lodging police complaint about the harassment and was expelled from the party.
Opposition parties led by DMK have accused the AIADMK of attempting to shield the accused, a charge denied by it.
The state government on Tuesday decided to recommend a CBI probe into the case.
According to police, the four had allegedly tried to strip the woman inside a car near Pollachi and had shot a video of the act and blackmailed her using the visuals and tried extortion.
The woman, who managed to free herself from the gang, lodged a complaint with police on Feb 24.
Meanwhile, protests by college students and various organisations were staged here and Pollachi on Wednesday demanding stern action against the accused and expressing solidarity with the woman, police said.
A bar owned by the expelled AIADMK functionary was ransacked by an irate group.
DMK Rajya Sabha member Kanimozhi had led a protest by party workers on Tuesday and a case had been registered against her and others for holding the agitation without police permission.