The order was passed by Additional District and Sessions Judge Sutanuka Nag yesterday.
The 32-year old man had allegedly raped and killed his cousin at his home at Dhengashol village adjacent to the girl's house last week.
Her body was found packed in a gunny bag and hid under a cot in the man's house by neighbours after the girl's parents raised an alarm as she went missing.
The man is married and is the father of a child.
Police claimed that the man has confessed to killing the girl but not raping her. However, post mortem reports have confirmed that she was brutalised.