The body parts were found 14 metres below the water surface on Saturday by an amateur diver, just off the coast of Saltö near the Norwegian border.
Police described the find as “the kind of thing that you think you could only see on TV” and added that they were unsure whose body it was, or why the pieces had apparently been wrapped up together and thrown into the sea.
On Tuesday, police announced their suspicions that the body was recently dumped.
“Several finds down there, including the body, suggest, in my judgment, that it’s not been there for long. But I couldn’t be sure if it was days, weeks, or months,” Thord Haraldsson of the national police told the TT news agency.
Police are now working with marine biologists and other experts to determine how long the body may have been on the seabed.
“We don’t know anything. The coroner is going to pull out the pieces tomorrow and take some X-rays. The autopsy will be carried out on Friday. By then, we will know the age and whether it’s a man or a woman. We have nothing until the coroner has done the job,” Haraldsson said.
Swedish police are cooperating with Norwegian officials as the body was found close to the border.