A body of a man in a decomposed state was found floating in the Cauvery river at Mukkombu, a few kilometres from the city, on Sunday.
The identity of the deceased, aged around 35 years, is yet to be established.
There were tattoo marks on the arms containing couple of names.
The body was sent for a post-mortem.
The Jeeyapuram police have registered a case of suspicious death, police sources said.