AHRC chairman Justice (Retd) Aftab H Saikia and member Tarun Phookan ordered the inquiry after the Commission took up the case suo motu following media reports of the custodial death.
Jorhat district magistrate will make enquiry into circumstances leading to the death and the report should be submitted within thirty days, an AHRC release said.
One Palash Baruah was arrested a fortnight ago for his alleged involvement in betting on IPL cricket matches and was lodged in Jorhat District Jail.
Family members of Baruah had alleged before the local media that he was suffering from illness when he was arrested and was also assaulted by some police officials in their custody.