Officers were contacted by the Ambulance service at around 12.15pm on January 18 with reports of the sudden death of a man in a flat in Riverside Heights in Tilbury.
He has now been identified as Steven Greenway of Riverside Heights in Dock Road, Tilbury.
A forensic post-mortem was carried out on February 13 which indicated the man may have been assaulted prior to his death.
Police are making enquiries to establish the circumstances surrounding his death and ask anyone with information to come forward.
Detective Inspector, Alan Pitcher said: “We are currently treating Steven s death as suspicious and exploring the possibility he was assaulted in Riverside Heights around January 13.
“Officers have been deployed to the area and neighbouring flats to attempt to build a picture of the events leading up to the his death.
“I m keen to speak to anyone who knows of Steven s last movements or anyone who may have heard a disturbance in Riverside Heights in the week commencing January 11.
Anyone with information is asked to contact Essex Police on 101 or Crimestoppers, anonymously, on 0800 555 111.