Det Supt Mike Brown from Suffolk Police told the inquest there were bags within bags, filled with shingle, rocks, some bricks and some soap products and air freshener products that became obsolete in 2011.
Asked by the coroner if he believed someone had wanted to ensure the bags remained sealed and did not smell, Det Supt Brown said “absolutely”.
Dive teams were also called to the scene where a second bag of bones was found slightly further down the river on 29 August.
They included pieces from a person’s skull and were linked by DNA to the first bags.
Det Supt Brown said the victim had suffered a “violent and unnatural death” and no DNA matches had been found on national or international criminal databases or databases for missing people.
The force believed there was a “criminal element” and that someone with “skills in butchery” had dismembered the body, he added.