Missing student Libby Squire “may have come to harm” since her disappearance two weeks ago, police have said in their latest statement.

The lack of progress in the search for the 21-year-old, which has involved hundreds of hours of CCTV being viewed, was worrying, said Det Supt Martin Smalley.

“Over the last two weeks, our enquiries into Libby’s disappearance have continued around the clock, with detectives and officers working night and day to find her and to understand what happened that night.

“While we do continue to be hopeful and we will always keep an open mind, Libby has been missing for 14 days now and we sadly have to consider she may have come to some harm,” he said.

The force also released photographs of clothes similar to those Squire was wearing on the night of her disappearance, including a black leather jacket, denim skirt and Vans trainers. Officers said the replica clothing had been donated by Topshop and put together with the help of Squire’s mother and her friends.

Clothes similar to those Libby Squire was wearing when she went missing. Photograph: Henry Clare/PA

Smalley said the police had not given up hope of finding the missing University of Hull student. “More work is now taking place behind the scenes rather than in public view, however this does not mean the investigation is slowing or coming to an end, it is exactly the opposite and is very much active and ongoing.

“We are determined and we will do all we can to find Libby – she is our priority.

“While I understand everyone will have questions in relation to the inquiries and searches we have carried out, at this moment in time we are not in a position where we can provide answers without jeopardising the investigation or any potential future prosecutions.”

Squire, a philosophy student from High Wycombe in Buckinghamshire, was last seen in Beverley Road in Hull after a night out. She was reported missing in the early hours of Friday 1 February.

In footage obtained by ITV News, a man can be seen getting in and out of a car minutes after she was last spotted.

The video, which Humberside police are investigating, shows the unidentified man opening the front passenger door, before getting back inside the vehicle and driving away at around 12.09am on 1 February.

On 6 February, Pawel Relowicz, 24, was arrested half a mile from Squire’s home on suspicion of abduction and police said he remains under investigation.

Relowicz was charged with a number of offences unrelated to Squire’s disappearance and appeared at Hull magistrates court on Monday.