The constable, Kavita Rawat, posted in the 8th battalion of ITBP, was found hanging from a hook in her barrack this afternoon, they said.
The body has been taken to a hospital for postmortem, police said, adding, the reason for Rawat's extreme step is yet to be ascertained.
In another incident, a 17-year-old girl allegedly committed suicide by hanging herself from a ceiling fan after her aunt scolded her for talking on mobile phone, police said.
Mamta Paneru, a Class XII student, was found hanging from the ceiling fan in her room in Vasant Vihar locality here last evening when her relatives returned from work.
Paneru, a resident of Haldwani town, was living with her aunt as she was pursuing her studies here.
A suicide note has been recovered from the room in which the girl held herself responsible for taking the extreme step. She has also apologised to her aunt in the note.