While the Chief Minister's office condemned it, the Criminal Investigation Department (CID) has taken up a suo moto investigation, official sources said.
"The Assam Rape Festival is not humorous. It is distasteful, unethical, abominable, despicable and must be abhorred by all sections of society," Bharat Narah, press adviser to Chief Minister Tarun Gogoi, tweeted.
Barnali Saikia Bora, Officer on Special Duty, said in a statement, "The fraudulent and extremely unethical article about the completely fictitious festival is an act of serious disrespect and total disregard shown towards the humble and unsuspecting people of our beautiful state of Assam".
"The details in the article are gruesome to the point of being demonic and the writer of such a piece of pure evil is not fit for human society," the statement said.
Amidst protests in the state, the CID's cyber-crime cell has taken up suo moto investigations into the website article which was found to have been sourced from Uganda and hosted from Houston in the US, the sources said.
The article, published last week on website NationalReport.net, claimed that the annual "Assam Rape Festival" that "began in 43 BC" was about "just days away".