Six-year-old Sana Parveen went missing on Monday from Bastipara area of Shibpur in Howrah district, they said.
Her family members lodged a missing complaint with the Shibpur police station alleging that she was kidnapped.
Today the body of Parveen was found near the Hanskhali khal area of Nazirganj in Howrah district, they said.
The body has been sent for postmortem, police said, adding, they have launched investigations into the matter to find out whether she was killed for ransom or not.