A 31-year-old man arrested on suspicion of rape by detectives investigating the "unexplained" death of 18-year-old student Caroline Everest has been bailed.
Sheffield Hallam University student Miss Everest was reported missing after leaving a Sheffield nightclub in the early hours of Sunday morning and her body was found in a river in the city on Tuesday.
The man, who was arrested on Wednesday, was released pending further inquiries, South Yorkshire Police said.
The force said the cause of death is still to be determined and is being treated as unexplained.
Detective Chief Inspector Victoria Short said: "I would like to say thank you on behalf of Caroline's family and South Yorkshire Police to the overwhelming public response we have had throughout the investigation so far."
She said it had been "an incredibly difficult time" for the family, adding: "The investigation is still ongoing and we are urging anyone who saw Caroline on the night she disappeared to come forward.
"Her picture has been widely circulated and if you saw her on that night please get in touch. Any information, no matter how small, could help us piece together her final steps to bring some closure to her family."
CCTV footage shows Miss Everest leaving the Corporation nightclub, on Milton Street, at around 2.40am on Sunday.
A minute later, she is seen with a man outside the Devonshire Cat pub, 50 metres up the road.
At around 3.35am, CCTV shows Miss Everest and a man parting company in Napier Street, close to where her body was found in the early hours of Tuesday morning.
Police sealed off a large area around the stretch of the Porter Brook where Miss Everest's body was found.
The river is little more than a stream at that point as it runs through an area of derelict land which was searched by officers.
The spot is about half a mile from the Corporation nightclub and close to Ecclesall Road, where many Sheffield students live.
Summerfield Street, where Miss Everest was last seen on CCTV, crosses the brook at the point where the police search was focused.
Napier Street crosses Summerfield Street about 50 metres further south.
Miss Everest's family, who live about four miles away in the north of Sheffield, became concerned when she did not turn up for work or a family dinner on Sunday.