Police searching for missing student Libby Squire say they are increasingly considering she has "come to harm," as new video of the Hull student was released.
The 21-year-old has not been seen since the early hours of February 1 near her home in Hull and her mother Lisa said it had been a month of “utter heartbreak and despair”.
Despite getting the assistance of national experts, including river search specialists, police have found no sign of her.
Today - one month on - officers released new home video of Libby in the hope it will lead to fresh information on her whereabouts. In the footage Libby is seen laughing in a kitchen, joking about a spider.
Detective Superintendent Martin Smalley, of Humberside Police, said: "Although we have followed up hundreds of leads and lines of enquiry and carried out intensive searches as part of the investigation over the last four weeks, as time passes by with no positive indication as to where Libby is or what has happened to her, Libby’s disappearance remains unexplained and we must increasingly consider she has come to harm."
"The investigation remains very much active and my thanks go out to everyone who has provided support and assistance as we continue to search for Libby," he added.
Libby’s mum, Lisa Squire, says the family is "incomplete" without their daughter.
She has appealed to anyone with information to come forward, saying: "It's now been four weeks without our beautiful Libby. A month of utter heartbreak and despair.
"We miss her more than we could ever say. We just want her back with us."
Last week Humberside Police released CCTV footage from the early hours of Friday 1 February. The force said a number of people came forward but were unable to offer any information leading to the identification of those in the grainy footage.
Footage obtained exclusively by ITV News shows a sequence of events officers believe may be related to her disappearance.