A body recovered from the Humber Estuary is female, but police said her identity has still not been confirmed.
Humberside Police have been searching for missing university student Libby Squire for almost seven weeks.
A post-mortem examination is taking place on Thursday, a day after the discovery was made close to Spurn Point.
Formal identification is expected to take place after the post-mortem, which police said is likely to last for the rest of the day.
A body was recovered at around 3.30pm on Wednesday and taken to Grimsby Docks, the force said.
Police said they have "informed those that needed to be made aware of the recovery".
Man arrested over Libby Squire disappearance charged with further unrelated offences
In a statement, Humberside Police said: "Formal identification is still yet to take place and we remain unable at this stage to confirm her identity."
Intensive searches involving hundreds of officers both on land and in water have taken place since Miss Squire disappeared last month.
Missing Libby Squire's heartbroken mum posts emotional appeal three weeks since disappearance
The last known sighting of the University of Hull philosophy student, originally from High Wycombe, Buckinghamshire, was just after midnight on Friday February 1 at the junction of Beverley Road and Haworth Street in Hull following a night out.
Last week, marking six weeks since she went missing, video footage of the happy and smiling student singing along in a car with her family was released as they said they miss her "beyond belief".
Grimsby Live say there are currently three active missing persons investigations being conducted by Humberside Police; Libby and two men who jumped from the Humber Bridge in December.
