The force is offering £5,000 for information which leads to the recovery of the body of Bogdan Nawrocki.
The 22-year-old was last seen in January 2014 close to his Radford home. He has not been seen since and following forensic evidence the force has mounted a murder inquiry.
In April 2014 27-year-old Robert Marcinkiewicz-Szukowski, of Rossington Road in Sneinton, was charged with his murder. Four men also arrested in connection with the murder have been released on bail.
Detective Chief Inspector Tony Heydon, who is leading the inquiry, said: “Intensive searches have been taking place across the last months to find Bogdan’s body, including a search of a factory in Radford last week.
“We believe Bogdan has been murdered and our aim now is to find his body and give his family the justice they deserve.
“Bogdan’s sister Monica is being supported by Police and kept updated with developments – she deserves to know what has happened to her brother. We hope that this reward will encourage anyone with information to do the right thing and get in touch with us.”
Anyone with information is asked to ring the Police incident room number 0115 844 6913 or Crimestoppers on 0800 555111. A dedicated line manned by Polish-speaking officers has also been set up on 07785 573415.