Suffolk Police say more forensic tests need to be carried out on human bones discovered in Sudbury.
Officers were called just after 4.35pm on Thursday afternoon, (27 August), after bones were discovered inside two black bin bags in the River Stour near Meadow Gates and Croft Bridge.
Suffolk Police have said a Home Office post-mortem examination of the remains was completed this morning (Sunday 30 August) but couldn't identify the victim or establish cause of death so more tests are needed. Police warn it will be a lengthy process.
Temporary Detective Superintendent Mike Brown, the Senior Investigating Officer, said: "This initial examination has unfortunately not been able to move us any further forward at this stage. The remains will now be subject to further specialist forensic tests which we hope will provide us with more information.
"This process will take time, so it may be a little while until we are able to provide any further significant updates.
Det Supt Brown moved to reassure the public.
Specialist officers are continuing to search the area around the river and its banks, with the assistance of divers from the Metropolitan Police Marine Policing Unit.