The accused, Bhoora alias Hubblal and Munnalal, were caught by a mobile police team on the night of February 21 when they were reburying the headless body at the city's Tajganj cremation ground.
Police recovered the severed head and a spade from them.
Munnalal, a resident of Etah, was working at the cremation ground and his associate Hubblal of Itmaduddaulah was a history-sheeter.
During interrogation, they told police that the body was buried two days earlier. And on instructions of a tantrik that if the skull of the girl was burnt it could turn into gold, the duo conceived the plan.
Police said the family of the dead girl was being contacted.