A 25-year-old man has been arrested on suspicion of murdering Hull University student Libby Squire.
Her body was recovered from the Humber Estuary six weeks after she disappeared on 1 February following a night out.
Hundreds of police officers and members of the public were involved in an extensive search after 21-year-old Ms Squire was reported missing.
The man was held on Wednesday and has been released under investigation as inquiries continue, police said.
Det Sup Martin Smalley, of Humberside Police said: “A file is being prepared for the Crown Prosecution Service as the investigation progresses.”
Ms Squire was last seen at just after midnight near her home on Wellesley Avenue, Hull.
Later that morning she was reported missing and search specialists, dog handlers, underwater officers and the public began a search.
At one stage, about 200 students gathered in the rain as a show of solidarity and support for the student and her parents.
The body of the philosophy student, from High Wycombe, was recovered from the Humber Estuary on 20 March.
Appealing for information during the search, her mother Lisa said: “Libby, my darling pie, we just want to know that you are safe.”
In an emotional Facebook post following the discovery of her body, her mother said: “I cannot thank you enough my darling Pie for making me a mummy.”