Missing student Libby Squire can be seen joking with friends from university in new video released by police who say it is increasingly likely “she has come to harm”.
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.
Detective Superintendent Martin Smalley who is leading the investigation said his team had followed up hundreds of leads and carried out intensive searches yet her disappearance remained “unexplained”, and added: “We must increasingly consider she has come to harm.”
The video shows Ms Squire laughing with friends in what appears to be a student flat.
Her mother described the footage as lovely and “very Libby”.
She said: “It’s now been four weeks without our beautiful Libby. A month of utter heartbreak and despair.
“As a family we are incomplete. We miss her more than we could ever say. We just want her back with us.
“Please if anyone has any information no matter how insignificant it may seem, contact the police.”
Meanwhile, the detective said CCTV released last week showed four potential witnesses in Oak Road, none of whom have been identified.
Mr Smalley said: “Oak Road and the playing fields have been an area of interest throughout the investigation with resources deployed and extensive searches conducted. Our searches are continuing, with further searches in and around the River Hull.
“I am aware of speculation and theories as to what may have happened to Libby. These will be considered and explored as part of the investigation.”
The detective said a man remained under investigation for kidnap, but he said disclosing further details could jeopardise any future prosecution.
He added: “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.”