The deceased has been identified as Dona Chhetri. Her body was recovered from a house yesterday after receiving information from the neighbours, a Kolkata police officer said.
The girl was suffering from AIDS and had lost her mother six months ago, who was also a patient of the same disease, police said.
They added, "Her father, also an AIDS patient, had left the family long back and the girl was living with her 11-year-old brother and mother."
The incident might be a suicide case as injuries were found on her neck, police said, adding that post-mortem has been conducted and investigation is underway.