The case will be transferred to the CBCID wing of the state police (Representational)
A class 12 girl student was found dead in her hostel toilet in Tamil Nadu's Thoothukudi last night, the police said.
Police have recovered the student's suicide note from her hostel room and investigation is underway, they added.
Superintendent of Police L Balaji Srinivasan told NDTV that the girl mentioned some personal reasons in her suicide note, because of which she was disturbed.
"We can't reveal the exact details. Investigation is on," Mr Srinivasan said.
17-year-old Vaitheeswari, who was from Ramanathapuram district of Tamil Nadu, was "heart broken" after her aunt's death, a police official said.
"She had told another student from her school that this will be the last time you'd see me alive", he said.
The case will be transferred to the CBCID wing of the state police following a recent order by the Madras High Court.
The high court has ruled that deaths in educational institutions must be investigated by the state probe body, CB-CID.
Five class 12 students - four girls and one boy, and a class 11 student have died by suicide over the past few months in the state, largely citing academic pressure and fears over performance in the National Eligibility cum Entrance Test (NEET) for admission to medical courses.
Chief Minister M K Stalin had recently appealed to students to not give in to the academic pressure. "Turn your trials into achievements" he had said.
He also urged the teachers to "infuse mental strength" among students.