Weybread man Peter Stuart died of multiple stab wounds, according to Suffolk Police.
A post mortem was carried out on a body found in woodland near Weybread, believed to be that of Mr Stuart.
While our hopes for Sylvia’s safety are reducing with the passage of time, there remains the possibility that she is still aliveDetective Chief Superintendent Simon Parkes
He and wife Sylvia, of Mill Lane, had not been seen since May 28.
A 61-year-old man from Leicester remains in custody in connection with the investigation into the murder of Mr Stuart and the disappearance of his wife Sylvia.
Mrs Stuart remains missing.
Detective Chief Superintendent Simon Parkes said: “Our priority remains locating Sylvia and we are continuing to conduct searches in Weybread as well as making further enquiries.
“While our hopes for Sylvia’s safety are reducing with the passage of time, there remains the possibility that she is still alive.
“We are also actively working to find Ali Qazmaji and determine his movements since Saturday 28 May, and would ask that anyone with information contacts our incident room as soon as possible.
“The 61-year-old man arrested yesterday is still in custody as we work to find out what happened to Peter and Sylvia.”
Police have also issued an appeal to help trace Ali Qazimaj, of the Thurrock area of Essex. They say he is a “key person” they need to trace in connection with the enquiry.
Anyone with information can contact Suffolk Police through the incident room on 01473 782000.
Police are still waiting for formal identification of the body, but it is believed to be that of Mr Stuart.