A 25-year-old man arrested on suspicion of murdering Hull University student Libby Squire has been released under investigation, Humberside Police said.
Libby had been on a night out with friends when she went missing in February.
Humberside Police said: "The 25-year-old man arrested yesterday (Wednesday, 21 August) on suspicion of the murder of Libby Squire has been released under investigation as further inquiries continue."
Senior investigating officer, Detective Superintendent Martin Smalley, said: "Proceedings are active and I would remind people to please refrain from any speculation, as the investigation is very much live and continuing.
"There are further inquiries still being carried out and there are constant investigative developments and procedures that are ongoing."
He added: "The majority of the additional analysis stage is now complete, with a small number still pending final results. A file is being prepared for the Crown Prosecution Service as the investigation progresses.
"My heartfelt thanks go out to Libby's parents for their continued understanding and patience.
"They have been kept informed of all the developments in the investigation and they will always maintain our support."
Ms Squire's disappearance sparked a large police search, with officers releasing CCTV footage as they attempted to track her down.
Detectives initially treated the case as one of a missing person.
It later evolved into a murder probe after the student's body was recovered from the Humber Estuary some six weeks after she was reported missing.
Ms Squire had to be identified by her fingerprints, an inquest was told in the aftermath of her death.
Her mother, Lisa, wrote in an emotional Facebook post that "no family should have to endure" what they had been through.
She continued: "No sisters should have that special girl they have known for all their time on this earth taken from her."
"No 11 year old brother should have his idol taken from him.
"No dad should have his first born little girl, his princess, taken from him.
"No grandparent should lose their first born grandchild.
"No aunt and uncle lose their first born niece.
"No mother should have to watch her family go through all of that."