A severed head of a man was found in a polythene bag with a letter beside it near Kamakhya temple atop the Nilachal Hills here on Friday, police said.
A woman rag-picker found the bag near Kamakhya Nursery and informed the local people about it, who in turn called the police.
The police found that the letter had the names of Goddess Kali written on it but suspect that it was put there to make it appear like a case of human sacrifice.
The police suspect that the unidentified man was killed in a pre-planned manner.
A massive search operation with sniffer dogs has been pressed into service to find the body of the person.
Local residents alleged that the killing was done with the intention of defiling the atmosphere surrounding the holy temple.