Tests to establish the cause of death of Sheffield student Caroline Everest are expected to take weeks to complete.
Police say they will provide an update about the investigation once they have more information after an initial post-mortem proved inconclusive.
The 18-year-old disappeared after a night out in Sheffield in the early hours of Sunday, November 22. Her body was found in Porter Brook two days later. A 31-year-old man has been bailed after being arrested on suspicion of rape.